ECOMMERCE 2.0 - Update

You'll find aspects of ecommerce and "content commerce" in many other Web 2.0 categories - wherever the founders are concerned about creating more or less serious revenue streams around their ventures.
Since the fall of 2006 I only add cases that have something original to show.

43deals - Find best deals
Adgenta - Add ads to your site, blog or rss feed
Amazon* - Shop, sell, review & rank
Ándale - Small online business sales tools
Apartmentratings - Rent after reading tenant's review & rating
Auctionmapper - Find auctioned goods nearby (mash-up)
Aytozon - Comparison shopping from Amazon & Ebay
Baeboo - Shop comparison
Bigcartel - Start, review & recommend online shops
Blish - Buy or sell your media
Blockrocker - Buy & sell thru classifieds; map mash-up
Blogbuy - Social market place
Bloggerkit - Let Amazon exploit your blog
Booksforschool - Buy & sell used text books
Broadbandgenie - Find best provider
Cafépress - Design, sell, buy
Carbonmade - Publish & manage your portfolio online
Clipfire - Shop search engine & community
Closo - Start & advertise your online shop
Cogteeth - Create T-shirt with personal coded message
Cooqy - Find things faster on Ebay (client)
Correlates - Parallel product search
Cottonrape* - Shopping game
Coverpop - Mash-ups of everything
Craigslist* - Post & read classifieds
Crowdstorm - Add & research products & share opinions
Darmik - Sell & share profits with charities
Dawanda - Social market place for people producing or buying handicraft (private beta)
Dealbundle - Social shopping (Stealth)
Dealcritic - Digg offers
Dealmine - Personalize your best deals
Dealplumber - Find deals & coupons
Dealspl - Social shopping community (stealth)
Dealsplus - Share hot deals
Dealtagger - Find & share good deals
Diversetrade - European alternative to (higher rates of) Ebay
Dnastylelab - Design, wear & share your own products
Dsimobile - Start an mvno network
Ebay* - Sell, rate & buy; auction
Ebaywiki - Wiki on things you can buy & sell
Edoc* - Fashion ecommerce goes alternate reality game
Elkhuistekoop~ - Bookmark your interest in a house that's not for sale yet, and get broker's help to show your interest to owners
Emongoo - Tools & marketplace to sell your property
Etsy - Buy & sell handmade things
Factorious - Hosted ecommerce inc marketing (Stealth)
Farecast - Get alerts for flight fares at your level (Stealth)
Fashmatch - Match your clothes
Fatfingers - Get better deals on Ebay thanks to typos
Fivelimes - Green shop aggregator
Flipadisc - Trade media
Flippid - Post what you need, and get an offer
Flyspy - Graph all of your choices in air travel
Fotogopo - Animated local route map; Google Maps & Geocoder mash-up
Froogle* - Local shopping search engine; Google Maps mash-up
Frucall - Mobile price comparison
Fuzzbo - Kill real estate agents (Stealth)
Garbagescout - Find treasures on NY streets; Google Maps mash-up
Gochaching - Simple shopping cart (Stealth)
Googlebooks - Publish & sell access to your? books
Greenleafmarket* - Buy or sell local products
Gumshoo - Auction analyzer; Ebay mash-up
Hawkee - Tagged price comparison
Hngry - Rate & pick your restaurants
Homethinking - Search, find, contact & review realtors
Hotpads - Houses for rent
Igglo - Get buy alerts for houses that aren't for sale yet (Finnish)
Imagekind - Start your own art galery online
Innertee - Design, mix, wear, share & sell
Inods - Shopping review aggregator
Insideflyer - Convert loyalty points
Insiderpages - Social directory guide
Jellyfish - Shopping search engine
Judysbook - Review & rate your neighbourhood
Kapaza~ - Free classified ads marketplace
Kayak - Price comparison with user input for travel
Kayakbuzz - Find cheap destinations; Google Maps mash-up
Külist - Search, compare, bookmark best prices
Lala - Swam CDs, from July 4th
Licketyship - Home-delivery supermarket; retail & couriers co-operation
Licketytrip - Last minute vacation rentals (map mash-up)
Lightenment - Publish & share reviews of gadgets
Limbo41414 - Dutch auction
Listd - Accelerate your Ebay listings
Localspring - Social yellow pages directory
Lopico - Social business directory
Mapeire - User generated lowest price finder; Google Maps mash-up
Mashmap - Find movies & showtimes (map mash-up)
Mecommerce - Resell stuff thru your blog
Moblee - Opt in to offers direct to your mobile
Mobsaver - Price comparison thru your cell
Modoshi - Shopping community
Motionmall - Design & insert webads
Mpire - Track price trends when you shop
Mrdealio - Compare & track prices
Mynewplace - Find & rent your new home
Mystyledesigns - Your body, your shape, your clothes - mass customized (stealth)
Mytriggers - Price comparison alert services
Nakedandangry - Design & share your wallpapers
Nestoria - Property search
Offertrax - RSS-based shopping alerts
Onsofts - Ebay & Amazon combined shopping search
Ourstockworks - Upload, sell or buy stockphotos
Paguna - Travel booking with 1 page Ajax interface
Peerflix - List & trade DVDs
Pricenoia - Amazon price comparison
Pricheck - Check prices continuously
Qloud - Social music search & buy service
Qoop - Publish & sell photos & photo products
Redtoucan - Share photos & review products
Reevoo - Review & buy electronics
Rentmeavacation - Share your vacation homes
Revver - Upload, share or sell your videos
Rightcart - Sell your own or 3d parties' stuff on your site
Savedsearchpro - Find Ebay deals easier
Savemyass - Send your wife flowers frequently
Sexycanvas~ - View & purchase erotic art (Browse through tastefully decorated rooms or upload an image of your own room to experience the works in various settings).
Shoposphere* - Create & share pick lists
Siteflavoredgoogle* - Tailor adwords to your site
Sizeasy - Compare sizes of online goods with everyday items
Skombo - Sell & buy rare music
Slister - Bookmark & list products
Solomodels - Upload, commicate with, vote for, hire or buy from photographers & models
Souki~ - Local shop search
Spotscout - Find or sell parking space
Spreadshirt* - Design, buy or sell your T's
Spymedia - Publish & sell news photos
Start12*~ - Find, compare & review online service providers
Streeteasy - Share shopping info
Stuffspace - List & share what you own & what you want
Stylefeeder - Find, share & keep track of cool products
Stylehive - Get recommendations fitting your product interests
Subscribecast - Sell content thru RSS-based subscription format
Superstart - Personalized shopping portal (Swedish)
Swapsimple - Trade your media
Switchdiscs - Trade media online
Tastydrop - Submit & rate wines
Tenbills - Design & buy your T
Terk~ - Meta search for articles
Thandora - Tag based search in yellow pages
Themintpages - Recommend & share reviews on beauty products
Thisnext - Shopping recommendation network
Threadless - Submit & rate T-shirt designs
Tictap - Price comparison for mobile
Tnook - Build, manage & trade your collections
Triporama - Plan, research & book trips together
Trustedopinion - Social recommendations engine (with visualisation of trusted circle of friends)
Uask - Sell or buy for the price you want
Viewr - Publish on map & buy or sell homes, globally
Vitalsource - Publish & sell or buy books
Watchingthewebflyby - Animated logo race
Watchthisnext - Vote for & buy DVDs
Wazima - Coupon aggregator
Web20milliondollarhomepage - Pixel ads
Web2carz - Shop for cars, publish & share reviews of dealers
Weedshare - Play, buy, share & sell music
Whabam - Search, buy & sell
Whatsbuzzing - Search, browse & discover products with a buzz
Whowouldbuythat - Anti-ecommerce
Wikology - Business directory wiki
Wists - Share shopping lists
Wize - Product review aggregator
Wuraweb - Find local prices & credentials
Yelp - Find, review & discuss local restaurants etc
Yokel - Find best prices for products near you
Yub - Meet, hang & get discounts in shopping mall
Ywoosh~ - Find or sell houses
Zazzle - Design, sell & buy custom goods
Zebo - List & share what you own & what you want
Zeedive - Social shopping (stealth)
Zillow - Get your home valuated (map mash-up)
Zipingo - Find local business based on community input
Zixxo - Create & distribute online coupons
Zlio - Social commerce
Zunafish - Buy & sell old media items
Citycribs - Real estate marketplace

Italic = new. Update 061221, 070119.