Web 2.0 alphabetical: from Nabaztag to Pytagor

Italic = new.

NNN
N2yo* - Realtime satellite tracking - Geo
Nabaztag* - Get info & communicate thru wi-fi rabbit device - Communicate
Nabbr - Create & share lists - List
Naim - Encrypted instant messaging - Communicate
Nakedandangry - Design & share your wallpapers - Ecommerce
Nakido - Upload & share your files - Store
Namakkal - Store, share & tag bookmarks - Bookmark
Naslu - Store & share code - Software
Nat1ion - Chat while you surf - Communicate
Nationofmillions - Submit & rate hiphop - Rate
Nativetext - Translates rss in foreign languages - Office
Naughtyamerica* - Multiplayer video sexgame - Game
Naughty-au-naturelle* - Penthouse letters map mash-up - Geo
Nav4all~ - Mobile navigation app, claim & share places with friends - Geo
Navdog - Organize & manage events - Office
Navteq - Global mapping dbase & technologies - Software
Nayio - Record your music, add video & share - Multimedia
Naymz - Edit & share your own online meta profile - Identity
NBBC - B2B marketplace for video syndication - Video
Ñblog - 2.0 blog - About
Nearbie - Explore or contribute to history of people, places and events - Publish
Near-time - Share resources & collaborate - Productivity
Neato - Tagging plug-in for Wordpress - Tag
Neavetv - Vote for shows this guy has to watch - Video
Nederkaart~ - Refers to map mash-ups (many Dutch) - About
Neighbor - Q&A (local) - Knowledge
Neighboroo - Explore USA trends on map - Geo
Neighborrow - Borrow from, lend to or trade with neighbours, friends & strangers - Economy
Nelements - Take notes in 3D - Office
Nellymoser - Mobile content delivery solutions - Software
Nenest - Create forms & dbases without programming - Software
Neobinaries - Web 2.0 developers, users & experts - Community
Neokast - Live video streaming platform & network - Video
Neoows - Tag, comment, share & discuss news - Community
Neptune - Manage tasks - Office
Nestoria - Property search - Ecommerce
Netcipia - Blog & wiki hosting - Publish
Netcocktail - Share colour schemes - Design
Nethaggler** - Track & negotiate prices - Ecommerce
Netlog - Publish & share photos, blogs etc & make new friends - Community
Netlog - Publish & share photos, blogs etc & make new friends - Community
Netmeshlid - Manage your online digital identity - Identity
Netnewswire - RSS reader (OS X) - RSS
Netomat - Share profiles, blogs, photos, etc - Community
Netscape - Edited & dug news - Rate
Netsquared - Share stories on remixing the web - Publish
Netsuite** - Manage all your business in one integrated suite - Productivity
Netvibes***** - Personal portal - Startpage
Netvouz - Social bookmarking - Bookmark
Networkltd - Share research - Knowledge
Networthiq - Track, share & compare your net worth - Finance
Neurosky - Bionic interface technology - Design
Nevow - Python web app construction kit - Software
Newradio - Find & vote for news - News
Newroo - Memetracker (Stealth) - Search
Newsalloy - Discover, read & share news - News
Newsaloud - RSS2voice - RSS
Newsatseven - Get your customized video news cast - News
Newscloud - Digg news - Rate
Newser* - Algorithm-based news aggregator - News
Newsfire - RSS reader (OS X) - RSS
Newsfutures - Trade on tomorrow's news today - Gamble
Newsgarbage - Post, moderate & control news - News
Newsgator - RSS reader (web & mobile) - RSS
Newshutch - Feedreader - News
Newsisfree - Personalize your news - News
Newskicks - Submit & rate articles for game developers - Rate
Newsletterarchive* - Store & share your newsletters - Communicate
Newslife - RSS reader (OS X) - RSS
Newsmap*** - Rank-interfaced news (who knows what happened to Hives?) - News
Newstoday** - Publish & share cool jobs, gadgets, etc - Community
Newsvine - Read, write & discuss news - News
Newzbubble - Watch your news in bubbles - News
Newzie - Monitor & aggregate news - News
Newzingo - News tag cloud; Google News mash-up - News
Newzpile - Aggregates tags-based feeds from many sources - RSS
Nexbig - Vote for the next big thing - Rate
Nexidia - Transform av data into business intelligence - Software
Neximage - Online imaging - Images
Nexo - Collaboration tools - Productivity
Nextaris - Social search - Search
Nextcat - Platform for entertainment professionals - Economy
NIM - Wireless navigation apps for mobile phones - Geo
Nimbuzz~ - Free mobile community calls, chats, IM - Communicate
Ning - Create social apps - Software
Ninjawords - Dictionary - VAS
Nirbi - Find matches for carpooling - Economy
Nitro - Ruby and JavaScript web app framework - Software
Nivio - Access your desktop from anywhere - Office
Nnseek - Forum search engine - Search
Nnseek - Forum search engine - Search
Nogoodtv* - Uncensored tv - Video
Noisely - Enter your favourite music & get continuous podcasts to your taste - Audio
Nomos~ - Live reporting on sound levels around Amsterdam Airport - Geo
Nonoh - VoiP - Communicate
Nooked - Manage & commercialize your feeds - RSS
Noovo - Create a website & share with other users - Software
Nooz - News for Myspace members - News
Notebookg - Make & share notes - Office
Notecentric - Take notes online - Office
Notefish - Compile & share notes online - Office
Notlong - Shorten your URL - Software
Nottr - Publish & share notes - Office
Novlet - Collaborate on writing - Productivity
Nowlive - Create live, interactive talkshows - Audio
Nownow - Ask a question, get three answers by email - Knowledge
Nowpos - Voice2Email community - Communicate
Nowpublic - Share, submit & revenue share news content - News
Nowsy - Customizable startpage - Startpage
Nowthen - Publish & share mobile pics - Images
Nozbe - Manage tasks - Office
Nsite - Operating system - OS
Numarketing~ (formerly: Keepaddit) - Digg on marketing - Marketing
Numbler - Excel spreadsheet online - Office
Numinalmeme - Share & vote for ideas - Knowledge
Numly - Tag & protect your content with serial numbers (formerly ESBN) - VAS
Numsum - Collaborate online on spreadsheets - Office
Nutclothing - Customize & order your handsprayed T - Ecommerce
Nutrax - Monitor & modify eating habits with your camera phone - VAS
Nutsie - Play your music on your cell - Audio
Nuvutv (formerly: Mediascrape) - Channelled tv - Video
Nuvvo - Build, publish & learn from courses - E-learning

OOO
Obopay - Global mobile transaction solutions - VAS
Octopz - Collaborate on & in any file format - Productivity
Octora - Search & share feed bookmarks - RSS
Octro - Mobile instant messenger - Communicate
Odeo - Record & share audio - Audio
Odesk* - Work as or hire remote workforce - Employment
Odinjobs - Job board for techies - Employment
Odiogo - Convert feeds to speech - RSS
Offermatica - Test & optimize your online marketing - Marketing
Offertrax - RSS-based shopping alerts - Ecommerce
Office-20database - Detailed spreadsheet with online Office-like apps - About
Officezilla - Free collaboration solutions - Productivity
Ogle - Capture, re-use & 3D print 3D data - Personal manufacturing
Ohloh - Search indexed open source projects - Software
Oihoi - First specify category, then search - Search
Okaytoplay - Tools & resources for podcasters & vloggers - About
OK-cancel - Collaboration on interface design - Design
Oks - Digg news - Rate
Omea - Manage & enhance your feeds - RSS
Omgili - Search discussion forums - Search
Omnidrive* - Store & access data - Store
Ondergrond~ - Upload photos of public art - Images
Onedump - Store & share - Store
Onellama - Share your musical tastes & get recommendations - Audio
Onemonkey - Make some money on accepting text link advertising - Marketing
Onerandomsite - Add & share links & surf at random - Bookmark
Onesens - Send teasing webmail messages - Communicate
Onestatement - Track your expenses - Finance
Onetruemedia - Mix & share videos, photos & music - Multimedia
Ongopongo - Search, create or submit & share maps - Geo
Onlinebookmarkmanager - Social bookmarking - Bookmark
Onlinegroups - Create a site, a group, invite & collaborate - Productivity
Onlinephototool - Photo editor - Images
Onlinewritingjobs - Gig directory for freelance writers - Economy
Only2clicks - Speed-dial startpage - Startpage
Onlywire - Social bookmarking aggregator - Bookmark
Onmycity - Upload, post & share everything locally - Community
Onnetworks - Watch & contribute to online how to-tv channels - Video
Ononemap - Find housing (map mash-up) (UK) - Geo
Onsofts - Ebay & Amazon combined shopping search - Ecommerce
Ontoworld - Semantic web wiki-community - Community
Onxiam - Aggregate your digital personae & find similar meta-profiles - Identity
Oodle - Find local classifieds - Search
Ookles - Upload & share photos - Images
Oolsi - Share links to free things - Economy
Ooma - Free phone calls over landlines - Communicate
Oomia - Lost & found - Economy
Oondi~ - Publish & share your text - Publish
Oovoo - Talk face-to-face over the web - Communicate
Oozm - Search refined by people - Search
Openacs - Content management system - Software
Openarchiteturenetwork - Share, review & collaborate on architectural projects - Community
Opencms - Content management system - Software
Opendiary - Publish your blog - Publish
Openfire - Enterprise VoiP and chat solutions - Software
Openid - Distributed identity system - Identity
Openinhoud~ - Share links to and reviews of open source software - List
Openkapow - Mash-up editor & hosting - Software
Openlayers - Put a dynamic map on any web page - Software
Openmedianetwork - Multimedia epg - Multimedia
Openomy - Upload your files & use extra apps - Store
Openpeople - Invite your friends & explore your network - Community
Openrico - Open source Java library - Software
Openstreetmap - View, edit & use geographical data - Geo
Openstudio - Create, collaborate, share, buy & sell - Economy
Openteams - Collaboration tools - Productivity
Openvlog - Upload & record video - Video
Openwave - Adaptive mobile suite for content, communications and context solutions - Software
Openwengo - Make free PC to PC video and voice calls over IP & communicate with your IM contacts - Communicate
Operator11 - Create, edit, remix, view & share videos - Video
Opinionaggregator - Q&A - Knowledge
Opinity - Manage your reputation - Community
Opinmind - Connect opinions to people (bloggers) - Search
Opmlicons - OPML Icon project - RSS
Opmlloader - OPML reader Web based - RSS
Opmlmmanager - OPML reader Web based - RSS
OPMLsearch - Dedicated OPML search - Search
Opmlsurfer - Read OPML Web based - RSS
Opmlvalidator - OPML validator - RSS
Opmlworkstation - Edit, manage, convert & share OPML + PPT2OPML - RSS
Opmom - Community for mothers - Community
Opod - Ajax OPML & RSS widget - RSS
Opsdo - Meta search - Search
Opsource - SaaS enablement and delivery platform - Software
Optevi - Get feeds & contextually relevant related news, blogs & discussion pages - News
Optimal - OPML widget - RSS
Opuzzvoice - Make money on doing voice overs - Economy
Orangoo - Spelling checker - Office
Orb - Stream your media, wherever - Multimedia
Orbeon - Create Ajax forms - Software
Orbitfiles - Store, access & share files - Store
Orca - Online personal desktop - OS
Orcaa - Move your desktop to a homepage - OS
Orchestrate - Task manager - Productivity
Organizedwisdom - Publish & share your wisdom on health matters - Knowledge
Orgasms2~ - Share creativity & inspiration - Community
Orgoo - All your communications integrated in one dashboard - Communicate
Orkut - Connect to your friends - Community
Oryanoo - Virtual office & CRM suite - CRM
Osviews - Submit & rate technology - Rate
Oszone - Share code - Software
Otavo - Collaborative web search - Search
Ourchart - Community for lesbians - Community
Ourmedia - Store & share data - Store
Ourstockworks - Upload, sell or buy stockphotos - Ecommerce
Ourstory - Tell & share the story of your life - Publish
Outfoxed - Social search - Search
Outorin - Gated community - Community
Ownskin - Create, explore & share mobile themes - Multimedia
Ownyourc* - Get help in making choices - Knowledge
Oyax - Social bookmarking - Bookmark
Oyco - Meta communications toolkit - Communicate
Oyogi - Share Q&A - Knowledge
Oz - Mobile IM, email & social networking solutions - Software
Ozmozr - Import, store, share & manage feeds in bulk or individually - RSS

PPP
Packagemapper - Track your package on a map - Geo
Pagebites - Resume search - Employment
Pagebull - Visual search - Search
Pagecharts - Compare Alexa scores of up to 5 websites - About
Pageflakes - Personal portal - Startpage
Paguna - Travel booking with 1 page Ajax interface - Ecommerce
Paird - Social matchmaking - Date
Pairup - Find & connect to fellow travellers - Community
Palary - Ajax browser - Browse
Paltalk - Videochat for social networks - Communicate
Pandafile - Store & send - Store
Pandion - Instant messenger (Jabber client) - Communicate
Pando* - Store & share data - Store
Pandora*** - Personalized radio - Audio
Pandorafm - Mash-up of Pandora & Last.FM - Audio
Panjea - Upload & share content, and get paid for it - Multimedia
Panoramio - Store your geo-tagged photos on Google maps - Geo
Panthius - CRM solution - CRM
Papla - Instant messenger (also mobile) - Communicate
Papoo - Content management system - Software
Parakey - Web OS - OS
Parbet - Betting exchange - Gamble
Parlano - Group dialogue & document sharing - Productivity
Particls - RSS reader (Windows) - RSS
Partypoker - Poker tournaments - Gamble
Partystrands* - Let partygoers interact with you & each other IRL, mobile & online - Community
Partysync - Meet & sms people - Community
Partyvibes~ - Publish & share parties in Holland - Geo
Pastehere - Copy-paste whatever & publish it - Publish
Pawspot - Exchange pet care - Economy
Payperpost - Buy a buzz in the bloggosphere - Marketing
Payplayfm - Music download store - Audio
Payscale - Get & share salary information - Employment
Paystage - Manage your projects - Productivity
Payter~ - Pay with your mobile phone - VAS
Payu2blog - Make money on writing reviews - Economy
Pbase - Host & share photos - Images
Pbwiki - Make a wiki - Publish
Pcastbaby - Store & share podcasts - Store
Pearbudget - Create your budget, track your expenses - Finance
Peasy - Exploit or book & rent parking space (UK) - Ecommerce
Pebblepad - Manage your documents - Software
Peekaboom - Label images in a game - Economy
Peekamo - Peekamo - Mobile community - Communicate
Peekface - Review employers - Employment
Peekkochat - Make every site a 'place' (Firefox plug-in) - Communicate
Peekyou - Editable white pages people finder - Identity
Peepel* - In-browser office apps - Office
Peerflix - List & trade DVDs - Ecommerce
Peerimpact - Swap video P2P and get paid - Video
Peerplink - Digg Web 2.0 websites (password protected) - About
Peerprofile - Publish & share your profiles - Community
Peertrainer - Buddy up, slim down - Community
Peetscom - Treemap product comparison - Data
Pegasusnews - Neighbourhood news, customized - News
People2pray - Manage & share prayer requests - Productivity
Peopleaggregator - Create or join networks, build & connect your community - Community
Peoplefeeds - Aggregate personal content - RSS
Peopleized - Get interviewed & promoted by other users - Marketing
Peoplejam - Get a better career, relationships, health, life by networking - Community
Peoplet - Plan & manage your career - Employment
Periodictable - Periodic table of the internet - About
Perooz - Mobile content portal - Startpage
Perplexcity - Treasure hunt (ARG) - Game
Personalinfocloud - Blog about ubiquitous content - About
Personalweb - Personalized portal solution (download) - Startpage
Persony - Organize & manage web conferences - Communicate
Perspectives** - Visualizes spatio-temporaly the places we inhabit - Data
Pervwatch - Perv mash-up - Geo
Phanfare - Upload & share photos & videos - Multimedia
Pheap - Content management system - Software
Pheeder - Alert all your friends with 1 phone call - Communicate
Pheedfire - Manage, measure & monetize your feeds - RSS
Pheedo - Make some money on accepting ads in your rss feeds - Marketing
Pheromonetrail - Share places & sites & persons - Geo
Phetch - Image treasure hunt (to help visually impaired people) - Game
Philoi - Social bookmarking - Bookmark
Philter - Flash feed reader - RSS
Phixr - Edit & publish your photos - Images
Phling - Listen to, explore & share music on your mobile - Audio
Phlog~ - Upload & share photos - Images
Phonefeeds - Read your feeds on your phone - RSS
Phonegnome* - Add VoiP to your PSTN, SIPped - Communicate
Phonezoo - Create & share ringtones - Audio
Photoblog - Phlog solution - Publish
Photobloggr - Find tags on name; Flickr mash-up - Images
Photobucket - Create, edit, upload & share photos & videos - Multimedia
Photocrank - Add graphics & caption to your cell cam photos & share them - Images
Photomap - Add photos to locations; multi mash-up - Images
Photorgy - Upload & share photos - Images
Photoshelter - Manage your photos - Images
Photoshelter - Store, share, buy & sell photos - Images
Photostack - Manage images (Ajax) - Images
Photostockplus - Submit & sell your photos - Images
Photosynth*** - Rebuild the world in photos - other users' and your own - Images
Photozook - Submit & rate photos - Rate
Photozou - Upload, share & publish photos & video - Publish
Phpcoder - IDE for PHP programmers - Software
Phpcomasy - Content management system - Software
Php-fusion - Content management system - Software
Phpnuke - Content management system - Software
Phpobjectgenerator - Object-oriented code for PHP apps - Software
Phpopenbiz - PHP framework for data centric business apps - Software
Phprojekt - Organize group activities & document sharing - Productivity
Phpwebsite - Content management system for communities - Software
Phrasr - Add photos to phrases; Flickr mash-up - Game
Phusebox - Community for sophisticated people - Community
Pic2color - Create color palettes from images - Design
Picaboo - Print photo book on demand - Publish
Picasa - Find, edit & share photos - Images
Picfu - Easy pic upload & sharing - Images
Pickdee - Organize & share competitions - Game
Pickle - Upload, explore & share videos & photos - Images
Pickle - Share videos & photos - Multimedia
Pickspal - Bet on sports with friends - Gamble
Pickspal - Compete with friends on sports bets - Game
Pickstation* - Listen to & digg music tracks - Rate
Pickupgame* - Find people locally to play games - Community
Picli - Submit & rate creative stuff - Rate
Picnik - Photo editor - Images
Pico - Search multimedia - Search
Picostation - Create & share your phone cam videos - Software
Picpix - Upload & share photos & videos - Multimedia
Picprizes - Publish & share photos, and win prizes - Images
Picsearch - Meta search on pics - Search
Picture2Life - Edit your photos - Images
Picture2life - Edit pics online - Design
Picturecloud - 360o view on your pics - Images
Picturepush~ - Store & share videos & photos - Multimedia
Picturesandbox - Photo & video search - Search
Piczo - Create & share website - Community
Pidgin - Meta instant messenger - Communicate
Piggy-bank - Semantic web browser (Firefox) - Browse
Pikapet - Create & send a personalized ecard - Communicate
Pikeo - Manage your photos - Images
Pikeo - Store, map, organize & share your photos - Images
Pikifx - Edit your photos - Images
Pimpmefamous - Submit & rate videos - Rate
Pinger - Instant voice messaging - Communicate
Pingerati - Share your microformats - Software
Pingidentity - Identity authentication solutions - Identity
Pingoat - RSS ping tool - RSS
Pingomatic - RSS ping tool - RSS
Ping-service~ - RSS ping tool - RSS
Pinppl - PIN messaging for Blackberry users - Communicate
Pipeline - Track your deals & organize your team - Marketing
Pipelinedeals - CRM & sales solution - CRM
Pipl - Search for people - Search
Pivot - Content management system for blogs - Software
Pixagogo - Upload, manage & share photos - Images
Pixelgroovy - Submit & rate tutorials - Rate
Pixelgroup - Draw anything with others - Design
Pixelmator - Photo editor - Images
Pixelmo - Digg games - Rate
Pixelnews - RSS reader (OS X) - RSS
Pixelotto - Click ads & win $ 1,000,000 - Marketing
Pixelperfect - Search stock images - Search
Pixenate - Photo editor - Images
Pixerus - Edit your photos online - Images
Pixilis - Upload & share or sell media - Multimedia
Pixilive - Upload, store & manage videos - Store
Pixpix - Bookmark & share media - Bookmark
Pixpo - Broadcast your video site - Video
Pixpulse - Upload & share photos and videos on your mobile - Multimedia
Pixrat - Social photo bookmarking - Bookmark
Pixsense - Take, manage & share cell phone pics & videos - Publish
Pixsy - Ajax-based image search - Search
Place4langs - Find people to practice or teach languages - Employment
Placeopedia - Wiki + Google maps mash-up - Geo
Placesite - Wi-fi portal & location communities - Community
Placestodo - Post & share places & things - Geo
Planedo - Post stories or vote for them - Publish
Planetminibox - Let your site visitors chat with you & each other - Communicate
Planhq - Collaborate on business plans - Productivity
Planiglobe - Create your own map - Geo
Planix - Organize & manage projects - Productivity
Planypus - Plan events with your friends - Office
Planzo - Arrange meetings & events online & thru sms - Office
Plateau* - Enterprise e-learning, performance & career management solution - E-learning
Platial - Co-create atlas & share places - Geo
Plaxo - Contact synchronizer - Office
Playdo* - Gaming community - Community
Playful-bent - Create erotic stories together - Porn
Playola - Listen to & collaborate on finding similar tunes - Audio
Playtxt - Socialize, flirt thru sms - Community
Plazes*** - Claim & share your locations - Community
Plazesbadge* - Show where you are (e.g. on your blog) - Geo
Plentyoffish - Reallyreallyreally free dating service - Date
Pligg - Includes social tools - Publish
Plime - Submit & rate anything - Rate
Plinkd - Social web hosting - Store
Plinkme - Publish your photos-widget or get photos for free - Images
Plogger - Open source photo gallery system - Software
Plone - Content management system for groups, communities, extranets and intranets - Software
Ploud - Build subscriber lists for RSS marketing - Marketing
Pluck - Social media solutions - Software
Plueballs - Bookmark, rank & share film news - News
Pluggd - Upload & share podcasts - Audio
Plugim - Submit, plug & share content - Economy
Plugoo - Take your IM to any page you want - Communicate
Plum - Collect, share, connect - Community
Plurn - List, listen to, create & share music - Audio
Plusmo - Fast, customizable way to get the web on your phone - Startpage
Pmachine - CMS - Publish
Pobb - Personal portal - Startpage
Pocketfuzz - Create & sell your own ringtones - Audio
Podango - Create a podcast station - Audio
Podbasket - Converts audio into feeds - RSS
Podbean - Upload & share podcasts - Audio
Podbop - Listen to bands that visit your city (Eventful mash-up) - Audio
Podbridge - Metrics for usage of podcasts - Marketing
Podcastalley - Digg podcasts - Rate
Podcastdirectory - Search podcasts - Search
Podcasterbater - Get your porn audio & video podcasts - Porn
Podcastfm - Publish pod & vod casts - Multimedia
Podcastnet - Search podcasts - Search
Podcastpeople - Publish your own multimedia show & make money on it - Publish
Podcastpickle - Share podcasts & vidcasts - Multimedia
Podcastsearchservice - Find podcasts - Search
Podcastspot - Free or premium podcast hosting - Store
Poddater - Create vodcast & connect - Community
Poderator - Store podcasts & create XML - RSS
Podesk - Publish & promote your vodcast - Video
Podfeed - Explore, review, create & share podcasts - Audio
Podfeet - Find casts - Search
Podlinez - Explore podcasts on your cell - Audio
Podnova - Find podcasts - Search
Podolicious - Personalized podcast news - News
Podomatic - Create, find & broadcast podcasts - Audio
Podsafeaudio - Upload & share your music casts - Audio
Podscope - Voice rec-based audio and video search engine - Search
Podscope - Find podcasts thru text search - Search
Pod-serve - Explore, publish & share podcasts - Store
Podshow - Podcast & vodcast network - Multimedia
Podtrac - Advertise in podcasts - Marketing
Pointment - Zaplet 2.006 for scheduling appointments - Office
Pokerlistings - Review, rate & rank poker websites - Gamble
Polarrose*** - Help to make the visual web searchable (stealth) - Images
Polldaddy - Create & publish polls - Survey
Pollgenius - Conduct polls - Survey
Pollground - Publish & participate in surveys - Survey
Polloo - Polls about happiness - Survey
Pollplaza~ - Collective polling - Survey
Pollpub - Create & share polls & contests - Survey
Poly9freeearth - 3D globe with various map layers - Geo
Ponyfish - Create feeds from any website - RSS
Pooln - Schedule your car pooling - Community
Pooxi - Upload & (revenue) share video - Video
Popcast - View & broadcast tv over ip (player) - Video
Poperti - Save your mp3 on a pop email account - Audio
Poperti - Enjoy music (and more) from your Gmail inbox - Multimedia
Popfly* - Create & share pages & mash-ups - Publish
Popist* - Social networking - Community
Populationone - Your pixel and 6.5 billion other ones - Economy
Popuri - Check popularity of any site - Data
Popurls - Folksonomied news - News
Porchlight - Bug tracking for small teams - Software
Pornalicious - Social porn bookmarking - Porn
Pornotube - A disgrace for the porn industry - Porn
Portableplaylist - List & listen to your sounds, anywhere - Audio
Portbooker - Search & book mooring, globally - Geo
Poserfish - P2P betting, free - Gamble
Post282 - Create community blogs - Publish
Postcastsender - Upload, share & get alerts for podcasts - Audio
Postful - Webmail2snailmail - Communicate
Postgenomic* - Share & rank life science knowledge - Knowledge
Posticky - Place, access & share notes (also mobile) - Office
Postr - Post bookmarks to many services - Bookmark
Postreach - Get your posting shadow-published on subject-relevant other blogs - Publish
Postsecret* - Publish & share secrets - Community
Postsecret* - Share your secrets thru sending in postcards - Publish
Postyourbeaver - Publish & share your nude photos - Porn
Powehousemuseum - Contribute to museum object folksonomy - Data
Powermap - Next level Google maps - Geo
Pptexchange - Create, edit & share your presentations - Office
Pptshare - Create, reduce size, organize & share presentations - Office
Praseus - Page rank based search - Search
Predixis - Discover, manage & enjoy music - Audio
Preezo - Compile & share presentations - Office
Prefound - Search & share what you've found - Search
Preloadr - Edit your photos - Images
Presentationengine - Create, edit & share your presentations - Office
Presto - Send email & photos to people who don't have a computer - Publish
Preventionweb - UN disaster risk reduction community. Looking for an experienced Web application developer (PHP, SOAP) who is not afraid of open APIs and CSS. This is a chance to get in on a start-up project and build a system from scratch; cf. https://www.xing.com/app/forum?op=showarticles&id=3441367&articleid=3441367. - Community
Previewseek*** - Byebye Google? (Coming back soon) - Search
Prezentit - Create, edit & share your presentations - Office
Pricenoia - Amazon price comparison - Ecommerce
Pricheck - Check prices continuously - Ecommerce
Primomailer - CMS for email newsletters - Marketing
Printeranywhere*** - Use your friends' printers - Office
Prismastar - Ecommerce solutions - Software
Prisonerlife - Prisoners community - Community
Processing - Share code for imaging, animations, sound - Software
Productwiki - Collaborative product info resource - Publish
Profcast - Record & publish your presentation - Office
Professionalontheweb - Submit & share your (company's) profile & portfolio - Employment
Profil3 - Get to know the people you play with - Community
Profilactic - Aggregate your digital profiles, content & friends - Identity
Profilefly - Aggregate & share your online profiles, contacts & bookmarks - Identity
Profilelinker* - Bring in all your profiles here - Community
Profileomat - Profile aggregator - Identity
Profy - Blog on Web 2.0 companies - About
Programmableweb** - Web 2.0 reference website, main source on APIs and mash-ups - About
Programmermeetdesigner* - Partner matching for IT projects - Economy
Project360 - Organize your projects on the web or on your pda - Productivity
Project4hire - Pitch for a freelance job - Employment
Projectip - Recognizes anything on your computer - Software
Projectopus - Publish, share or sell music - Audio
Projectpipe - Organize & manage projects - Productivity
Projectplace - Run & co-ordinate projects - Productivity
Projectplaylist - Publish & share music playlists - Audio
Projectspace* - Organize, manage & collaborate on your projects - Productivity
Projectspaces - Work together - Productivity
Projity - Organize & manage projects - Productivity
Promptu - Voice based search for all media - Software
Propaganda - Create & edit podcasts (client) - Software
Propelr - Manage tasks - Office
Properazzi* - Promote or explore European real estate - Ecommerce
Propsmart - Find housing (map mash-up) - Geo
Prosper - P2P lending - Economy
Prospero - White label community software - Software
Protectmyphotos - Back-up your photos online - Store
Proteus - Meta instant messenger (Mac) - Communicate
Proto - Create desktop mash-ups - Software
Protolize - Digg web tools - Rate
Protonotes - Make & share notes - Office
Protopage - Personal portal - Startpage
Prototype - JS framework - Software
Protus - Enterprise communication solutions - Communicate
Proworkflow - Manage your projects & time - Productivity
Proz* - Global collaboration platform for translators - Office
Prweb - Push press content to over 100,000 media - News
PSFK - Share trends watched - Marketing
PSI - Check your installed software for malware & updates - software
Psiim - Instant messenger - Communicate
Psiphon* - Surf the web anonymously - Browse
Pssdir - Create & publish your own search engine or web directory - Search
Pubet - P2P filesharing (client) - Software
Publicloos - Share public toilets - Geo
Publish - Create feed from anywhere - RSS
Publishing2** - Web 2.0 from a publishing & marketing point of view - About
Pubsub - Search + profiled alerts - Search
Pulverati - Create & share RSS feed search - Search
Purevideo - RSS startpage for videos - Video
Purevolume - Music community - Audio
Pushcrm - Web-based crm - CRM
Pushy*~ - Personal portal; also mobile - Startpage
Putfile - Upload, rate, share & discuss multimedia - Multimedia
Putfwd - Store & exchange data - Store
Putplace - Organize & share all your offline & online content - Productivity
Puzzr - Vertical search - Search
Pxn8 - Manipulate & publish your photos - Images
Pylons - Web framework using Ruby, Python & Pearl for rapid development - Software
Pytagor - Online desktop & collaboration tools - Startpage

Update 070527, 070831.