COMMUNITY 2.0: 324 ways to find back old friends or make new friends, to share & exchange emotions, opinions, content & other things you care about

Since doing things together is the most important denominator of Web 2.0, you'll find many more symptoms of community forming in other categories. But COMMUNITY 2.0 is still a HUGE category.

The funny thing with communities is that they've already proven to be attractive to a few hundred million people, but that only a few entrepreneurs really know what makes them tick. Finding a theme that makes people unite around a common interest isn't that difficult, but keeping them there - happy and active - and finding a sustainable reason to ask some money for being part of them (or to find other revenue streams) in most cases is still a challenge. The best effort presently comes from Facebook - you can't do without that one if you want to know what's going on in the wondrous world of Web 20!

Me too-propositions are numerous. Only 20 additions that I found worth mentioning in this update, in italic.

43people - Tag based matching & dating
43places - Publish & share stories about places
71miles - Read & contribute to regional travel portals
Adoppt - Publish & share
Agester - Let other users tell how old you look
Aim - Myspace for AOL users
Amateurillustrator - Publish, rate & rank illustrations
Amiamo - Find things & people you like
Amiglia - Publish & share family trees, photos, maps…
Attendr - Mash-up your conference or party
Badged - Add your social networking badges to your blog
Barcardz - Network in real life
Battleout - Challenge & vote for best, biggest etc. whatever
Bebo - Find back school & college friends
Begreen - Here it's easy being green
Bibliochat - Get book excerpts and reviews, and discuss books - live
Biznik - Business network
Blackplanet - Community for African-Americans
Blnk - Publish & share your profile and make new friends
Blogtronix - Blogging & corporate community software
Bookmooch - Exchange old books
Bookrevyoo - Social book review community
Bouldr - Share climbing (map mash-up)
Bringsome - Ask the world to bring you some, or bring something to someone else
Buurtlink~ - Find people, places & news in your hood
C4-world - Fight poverty by participating
Cambrianhouse** - Collaborate on new software
Capazoo* - Create, publish & share your content
Cerado - Networking platform for organizations
Chickadvisor* - Get & share advise on chicks in your city
Cingo - Keep your family together online
Citizenbay - Get yourself on the map & meet new friends
Citycita - Find likeminded people & meet them
Citytherapy - Share places, events & people
Collectivex - Communicate, share files & schedules, group-wise
Comagz - Co-create & rate content
Commongate - Create your own social network
Communitywalk - Share places & routes (map mash-up)
Consumating - Tag based dating
Corkd - Catalog, rate & review wine
Craftster - Share crafting ideas
Criticker - Rate films and get recommendations
Curbly - Share design & get advise on it
Customerforce - Search & share everything
Cyworld - Record, share & give
Dabble - Share, manage & explore your information
Daddaily - Community for dads
Dailystrength* - Share health challenges & get wellness support
Dandelife - Describe & share your life
Developerid - Community for web industry
Deviantart - Publish or buy from art portfolios
Dnaancestryproject - Trace & share your ancestry
Dodgeball - Hook in with your mobile & meet friends
Dollpalace - Create a doll & share it
Dontdatehimgirl - Women community
Dontstayin - Clubber community (UK)
Doostang - Community for professionals
Downelink - Gay community
Dudecheckthisout - Store & share bookmarks, lists with friends
Economie - Interact for a sustainable future - Community
Ekudoz - Give & receive kudoz
Eons - Babyboomers' community
Eroshare - Upload, explore, rate & share photos
Eroshare - Upload, explore, rate & share photos
Evnt - Publish & share RL events
Exaroom - Connect to & share files with family & friends
Experienceproject - Share your experience & meet people who understand you
Facebook*** - Student communities
Faceparty - Clubber community (UK)
Famiva - Collaborate on your family tree
Famster - Family community
Fanpop - Share bookmarks & meet fellow fanatics
Feelingbullish - Rate, view & discuss stocks
Flickrgraph - Visualize relationships inside Flickr
Flingr - Connect with people you've ever met
Fortuitos - Make friends by accident
Frappr - Put your group on the map, share photos
Frengo - Mobile entertainment & communications community
Friendping - Share map, media & bookmarks with friends
Friendsabroad - Meet & communicate with people globally
Friendster - Connect with friends
Frühstückstreff - Meet people for breakfast
Fuzzster - Meet pets & their owners
Gamervision - Publish & share profiles, news & blogs on gaming
Gearon - Social mobile network around your cellphone's contacts
Geek2geek - Find your geek match
Geesee - Provide chat services, or participate in chats
Geni - Create & share your family tree, in Ajax
Geotract - Share places & people
Gizmoojo - Geek community
Glee - Community for gays & lesbians
Gobignetwork - Community of startup companies
Goingon - Always on network of networks
Goodreads - List, review & recommend books
Gotzapp - Publish & share content thru your mobile
Groovr - Text to & network with friends
Groups - Create groups & share content
Gusto - Share trips with friends & family
Hamsterster - Community for hamster lovers
Hashbush - Meet your friends' friends
Hi5 - Connect & share ideas with friends
Hobeez - Find & make friends people with similar hobbies
Holotof - Pitch your ad project among creatives
Hoovers - Manage & connect to your personal & corporate networks
Hotsoup - Community for political debate
Hotspots - Network for urban professionals
Hotspottin - Share your favourite hotspots
Hoverspot - Publish & share your profile
Humblevoice* - Publish, share bands, music, other media & arts
Hyves~ - Share your profile in hyves & meet friends
I4giveu - Confess, share & forgive
Ideawhip - Community for students, alumni, start-ups
Ideawicket - Community for start-ups & innovators
Ikarma - Document & promote your reputation
Imagini* - Profile yourself with images & find people with similar visual DNA
Imbee - Secure networking & blogging for kids
Imity - Sense phones (and friends) around you thru Bluetooth
Industriouskid - Kid0friendly, parent-approved websites & apps
Invitika - Organize, report & share events thru your cell
Ipubble - List & promote your website & have it reviewed
Islandoo - Temporary (?) community for tv show's casting
Isporty (olim Tiredandtested) - Sports community
Ittoolbox - Community for IT professionals
Iugen - Publish your profile & see how connected you are
Iwiw - Find your friends
Jaiku - Social phone directory showing where you are (Nokia S60 2nd ed.)
Jambo - Discover who's nearby & reconnect live
Jibjab - Create & share your funniest stuff
Join2growbiz~ - Community for European entrepreneurs (by Fortis Bank)
Jyve - Get live answers on your questions
Karmadu - Thank people by sending them karma points
Karmus - Create, share & contribute to cards
Klostu - Aggregate all your communities in this one
Kluskring~ - Share ideas & knowledge on DIY
Konnects - Networking for professionals
Koolanoo - Jewish social network
Krawlerx - Create, search, share & build community around your media
Lightstalkers - Networking & discussion tools for professional travellers
Linkedin - Manage and share your cv
Livejournal - Join or create your own community
Loowa - Claim your email address, share your profile
Lostcherry - Social network for youngsters
Lovento - Find friends & events
Madville - Submit & share mad stuff
Mangezmangez - Publish, review & share restaurant information
Mapable - Build & share chatrooms & communities
Mapmix - Find your friends (map mash-up)
Matador - Global travel community
Mayasmom - Something with parenting
Me* - Build, manage & exploit your online community
Meet-a-local - Find local hosts in other cities (German)
Meetro - Find friends nearby (thru messenger)
Meetup - Find common interests & organize meetings
Miaplaza - Connect with friends, family etc.
Mikons - Create & share your own icons
Minglenow - Connect with places & people
Minitellus - Share your experience with & meet students
Minti - Parents community
Mizpee - Share information on nearby loos
Mmotr - Automotive (dating) community
Mobber - Create instant community & chat while you surf
Mobiluck - IM, text & share media on your mobile
Mojizu - Create & share characters
Mologogo - Share where you are
Mommybuzz - Moms connect with moms
Monsterdare - Create, do or sponsor a dare
Moob - Party scene community
Mothersclick - Share knowledge on motherhood
Mozes - Share information & people thru your mobile
Musichawk - Share the artists you're into
Mycool - Search, create & share special interest groups
Mydeathspace - Directory of dead Myspace members
Myfreeimplants - Get a boob job or help her get one
Myfrienemies - Connect with people, show & share the same dislikes, annoyances & disappointments
Mygamma - Mobile community
Mymovienetwork - Community for filmmakers
Myspace - Communicate with & share content with your friends
Mystrands - Share your taste, get recommendations & party
Myvtc* - Share media & documents for generations to come
Neobinaries - Web 2.0 developers, users & experts
Neoows - Tag, comment, share & discuss news
Netlog - Publish & share photos, blogs etc & make new friends
Netlog - Publish & share photos, blogs etc & make new friends
Netomat - Share profiles, blogs, photos, etc
Newstoday** - Publish & share cool jobs, gadgets, etc
Onmycity - Upload, post & share everything locally
Ontoworld - Semantic web wiki-community
Openarchiteturenetwork - Share, review & collaborate on architectural projects
Openpeople - Invite your friends & explore your network
Opinity - Manage your reputation
Opmom - Community for mothers
Orgasms2~ - Share creativity & inspiration
Orkut - Connect to your friends
Ourchart - Community for lesbians
Outorin - Gated community
Pairup - Find & connect to fellow travellers
Partystrands* - Let partygoers interact with you & each other IRL, mobile & online
Partysync - Meet & sms people
Peerprofile - Publish & share your profiles
Peertrainer - Buddy up, slim down
Peopleaggregator - Create or join networks, build & connect your community
Peoplejam - Get a better career, relationships, health, life by networking
Phusebox - Community for sophisticated people
Pickupgame* - Find people locally to play games
Piczo - Create & share website
Placesite - Wi-fi portal & location communities
Playdo* - Gaming community
Playtxt - Socialize, flirt thru sms
Plazes*** - Claim & share your locations
Plum - Collect, share, connect
Poddater - Create vodcasts & connect
Pooln - Schedule your car pooling
Popist* - Social networking
Postsecret* - Publish & share secrets
Preventionweb - UN disaster risk reduction community.
Prisonerlife - Prisoners community
Profil3 - Get to know the people you play with
Profilelinker* - Bring in all your profiles here
Qlique - Real-time location aware community
Rabble - Create it & share it mobile
Raisingthem - Publish & share parenting tips
Readme - Exchange info & compare notes on books
Redlightcenter - 3D adult community
Refurber - DIY community
Renkoo - Arrange when & where to meet your friends
Renkoo - Arrange when & where to meet your friends
Respectance~* - Come together to remember loved ones
Revish - List, discuss & review books
Rsvpbuy - Invite people to your auctions & events, or get invites
Saki - Mobile community
Sayswap - Game trading community
Schoolbank~ - Profile yourself & find back class mates
Selsius - Real estate community
Sharea - Manage what you share with whom
Sharecare~ - Organize yourselves in groups to share care
Shareyourlook - Community for fashion addicts
Shelfari - Show, review, share your books
Shoutcentral - Publish yourself & chat while you surf
Shoutfit - Share trends & friends
Shuzak - Community for geeks (with Digg-like features)
Skillswap - Swap your web design skills
Smikioo - Catch yourself smiling & get comments
Smutvibes - Hook up with hot friends, meet new people (adult stuff)
Snappages - Publish & share your life with this toolset
Snubster - Get rid of your friends
Socialexplorer - Find out about your neighbours
Sonopia* - Start an mvno; create your mobile & online community
Spokeo - Aggregate & share your social network profiles & content here
Sportsmates - Sports bloggers community
Sprinko* - Do & share everything here
Stardoll - Dress up & share your favourite celebrities
Startupping - Share knowledge on starting up a company
Stockarena - Post on stocks, get graded & make money with it
Stylespy - Publish, vote for & discuss trends
Sugar - Ecosystem of Women's communities
Suicidegirls - Sex (& culture) positive community of women (& men)
Superviva - Share & get ideas for a better life
Tagalag - Tag & map your contacts
Tagged - Tag yourself and the ones you love
Talicious**Share your talents (by uploading stuff) & get discovered
Tangler - Get together for groups, chat, debate & share whatever
Taumed - Share knowledge on health matters
Teebeedee - 40+ community
Thebeststuffintheworld* - Publish, discover & share cool things
Theblackstripe - Upload & share photos
Thebroth - Collaborate & share glob al mosaic
Theparalysiscommunity - Spinal cord injury community
Thoos - Social networking for athletes
Tickle - Lifestyle community
Tinfinger - Search persons
Toolstolife - Change yourself together!
Toongum - Publish & share flash cartoons
Towncrossing - Create & participate in communities
Trailfire - Log & share your clickpaths
Tribe - Connects you to friends, neighbourhoods & forums
Trig* - Create & share your network & content, get featured
Tripconnect - Publish & share travel advice
Triphub - Plan group trips
Tripmates - Meet locals, get tips - Community
Triptie - Mix your trip from trip plans by other users
Tubes - Create your own social network & share your stuff
Tubesnow - Create, invite & share
Tubesnow - Create, invite & share
U-lik - Build your virtual library & share it
Uplayme - Share music & meet people with same taste
Upscoop - Discover which of your friends are on social networks
Urbanplanet - Discuss urban (USA) issues
Urbis - Community for creative people
Vcarious - Travel community
Velvetpuffin* - Mobile community
Vertagio - Connect with friends
Vixo - Send, get & forward sms messages
Vles - Virtually visit & meet new friends in New York's lower east side
Wadja - Use & share the web on your mobile phone
Wakoopa~* - Create your software profile, share it & get suggestions for cool stuff
Wallop - Publish & share media
Wasabi - Share news with friends
Wayn - Log & share places & people
Webjam - Collect, mix & share content from many sources
Weekendr - Plan & share weekend activities
Weeworld - Create your avatar & share it everywhere
Wehanghere - Find, message & meet people in your favourite places (London)
Wesabe - Help each other to get the most from your money
Where - Upload & share photos on community walls & maps
Whereareyou~ - Diary for travellers, interns and expats
Whyrobbierocks~** - Style your avatar & travel with it around the world wide web
Witness - Improve the world through documenting injustice with videos
Xanga - Blog rings
Xing** - Community for entrepreneurs & professionals
Xuqa - Publish yourself & connect to anyone
Yatam - Share where & when you are going to be
Yfly - Meet celebrities, share content
Yippykya - Make new friends a/o get discovered
Yoc* - Share media with your friends thru web & mobile (German)
Yournextdrink - Publish, vote for & share drink recipes
Yuku - Share your profiles & media
Zaadz~ - Network of inspired people
Zexsports - Networking for extreme sports lovers
Ziggs - Index of professionals
Ziki - People matching thru tagged interests
Zingku - Text2website content sharing
Zoints - Publish & share your content, and meet
Zoodango - Have a coffee with other professionals
Zoominfo* - Search persons; create your own page
Zooof~* - Discover, maintain & extend your family ties
Zooomr~ - Find photos & make friends in many languages
Zopto - Add your stuff to & share places

Italic = new. Update 061221, 070119, 070303, 070517 (corrected 070527), 070829.