Social Network vendors to watch

Now that we've defined what we mean by Social Network, who are vendors in the space? According to FaceTime (not to be confused with Apple's video chat iPhone app), there are over 900 Social Network sites available today (http://research.facetime.com/appsguide.php).

Many of them are fledgling sites in niche area. But there are several that worth watching for one reason or another.

Let me create short watchlist:

Facebook, Twitter, LinkedIn, MySpace, Google Buzz, Cliqset, Vimeo, Wordpress, Tumblr, FriendFeed, Foursquare, Gowalla

In addition to these, there are enterprise intranet Social Network collaboration vendors:

Box.net, Sharepoint, Quad, Jive, Socialtext, Socialcast

Also there are a couple of interesting open standards and implementation available:

ostatus.org, Liferay, geoloqi.com, status.net, SugarCRM

I think we should drill into these in a bit to get the sense of Social Network landscape today, and to spot trends.