If you’re interested in the growth of social networking sites and their popularity, you’ll want to check out this article by Clive Thompson from the New York Times Magazine (thanks to Techdirt for the link and an introduction). The article gives a bit of insight into Facebook’s history and growth and moves on to discuss a concept called “ambient awareness”: 

Social scientists have a name for this sort of incessant online contact. They call it “ambient awareness.” It is, they say, very much like being physically near someone and picking up on his mood through the little things he does — body language, sighs, stray comments — out of the corner of your eye.

It’s a worthwhile read – share your thoughts in the comments.