I've caught the most aggressive virus I've ever had in my whole life: not a nasty little invisible body-invading parasite, but rather the mammoth time sink that is Facebook.
Of course I immediately began to speculate about what the attraction is. Here are my conclusions to date:
1) Facebook allows for the irresistible, if disgusting, self-indulgence of talking about oneself ...
2) ... without actually having to produce a sequence of thought at any point, because it's all framed for you already. (Intellectually and aesthetically speaking, the difference between blogging and Facebook is the same as the difference between an exam requiring you to write an essay-type answer and an exam involving multiple choice.)
3) Facebook has lots and lots and lots of toys. OOOHHHH, SHINY!