My favorite part is the "What Twitter Says About You":
The average Twitter user is likely to have low self-esteem and feel insecure. They counter these feelings by reaching out to everyone they know, and creating situations where they can be the centre of attention. Twitter users are probably a danger to themselves and to society.
But these are gems as well:
The users find salvation in badly animated GIFs, music that auto-plays their voices and taking 'sexy' camera phone profile portraits in front of dirty mirrors -- all common modes of expression. The number of friends in a user's list is a self-esteem barometer. Anyone will do, but their top five friends usually consist of anyone who's shunned pop culture, is partial to facial piercings and is in a grunge rock band.
Most Facebookers have mastered the skill of anonymous stalking. They're loathe to admit it, but they'll happily waste hours peering into the lives of people they hardly know, assimilating every last piece of personal information they can -- particularly if their victim is good looking.
To them, Facebook is the equivalent of breaking into somebody's home while they're away, reading their diary, trying on their underwear and (through the Facebook wall) scrawling graffiti everywhere.
Even if you don't know what any of these sites are, you've probably heard of them. And if you're looking for a nice little summary of each, it's not a bad resource.