- 43 Things Goal and Dreams,
- Advogato Free Software and Open Source developers
- Amina – Chechen Republic Online Chechens
- aSmallWorld European jet set and social elite
- Bebo Schools and colleges
- BlackPlanet.com African-Americans
- Blue Dot Link sharing
- Brasileiros nos Estados Unidos – Rede Social
- Broadcaster.com Video sharing and webcam chat
- CarDomain Car enthusiasts
- Care2 Green living and social activism
- Classmates.com School, college, work and the military
- Consumating “Consumeetings”
- Couchsurfing Hospitality
- Cyworld Young South Koreans
- Dandelife Collective narratives or “shared biographies”
- DeadJournal “Dark” blogs, based on LiveJournal
- Dodgeball.com Mobile location-based service, owned by Google
- DontStayIn Clubbing (primarily UK)
- Doostang Careers
- eSPIN Teens
- Facebook Started for colleges, then high schools, and now everyone.
- Faceparty British teens and 20-somethings
- Flickr Photo sharing
- Flirtomatic Flirting/Dating
- Fotki Photo sharing
- Fotolog Photoblogging
- Friends Reunited School, college, work, sport and streets
- Friendster General
- Frühstückstreff General
- Gaia Online Anime and Games
- Gather (website) Article, picture, and video sharing, as well as group discussions
- Geni.com Families, genealogy
- Graduates.com School, college, and work
- Grono.net Poland
- GuildCafe Online games Unknown Open
- hi5 General
- Hyves General Dutch social networking website
- imeem Music, Video, Photos, Blogs
- Infield Parking United States NASCAR fans
- IRC-Galleria Finland
- iWiW Hungary
- Jaiku Update friends with your status through SMS, IM, web interfaces
- Last.fm Music
- LibraryThing Book lovers
- LinkedIn Business
- LiveJournal Blogging
- LunarStorm Sweden
- MEETin General
- Meetup.com General
- MiGente.com Latinos
- Mixi Japan
- MOG Music
- Multiply “Real world” relationships
- My Opera Community General (blogs, photo albums, forums, groups, etc.)
- MyChurch Christian Churches
- MySpace General
- myYearbook General
- Netlog Formerly known as Facebox.
- Nexopia Canada
- Ning Make your own social network Unknown Open
- OkCupid Dating Unknown Open
- orkut Owned by Google. Popular in Greenland, Brazil and India.
- Passado General
- Piczo Teenagers, Canadians, photo sharing
- Playahead Swedish teenagers
- Playtxt Mobile social network, location, worldwide
- Pownce moblog for websites, files, and short updates Unknown
- ProfileHeaven British teens
- RateItAll Consumer ratings + social networking Unknown
- Reunion.com Locating friends and family, keeping in touch
- Ryze Business
- Sconex American high schools
- Searchles Social Search + Social Networking
- Sermo Physicians
- Shelfari Online community for book lovers Unknown Open
- Skyblog France, Belgium, French Polynesia, Guadeloupe, Martinique, New Caledonia, Senegal
- Soundpedia Web 2.0 based music community
- Sportsvite Recreational Sports
- Studivz University students, mostly in the German-speaking countries
- Stumbleupon Websurfing
- TagWorld General (tagging)
- TakingITGlobal Social action
- The Doll Palace Cartoon dolls and dress up games
- The Student Center Teens and colleges
- Threadless Custom T-shirts 364,474 Open
- TravBuddy.com Travel
- Travellerspoint Travel
- Tribe.net General
- Twitter Update friends with your status through SMS, IM, web interfaces
- WAYN Travel & Lifestyle
- WebBiographies Genealogy & Biography Unknown
- Windows Live Spaces Blogging (formerly MSN Spaces)
- Woophy travel & photography
- Xanga Blogs and metro areas
- XING Business
- Yahoo! 360° Linked to Yahoo! IDs 4,700,000 users and open to people 18 and older
- Zooomr Universal Photo Sharing
