I first went on Facebook in college in about 2005 or 2006. Back then, it was simple, less commercialized, and the only people on it were college students, so there was no risk of saying something your mom would hear. Anyway, I got a few dozen friends that were mostly just my classmates, but then I lost interest and de-activated my account. Then about a year later I went back and stayed a year or two until it exploded and now everyone and their godmother is on it. So finally I figured out how to actually DELETE my account (not just deactivate; go here: http://www.facebook.com/group.php?gid=16929680703), and I haven't been back since. And no, I don't miss it.
The thing I hate about it is hearing so much crap from my friend's friends, and then being tempted into interacting with them on my friend's pages. Made me realize how many idiots my friend's have for friends. Then again, others were probably wondering the same thing about me.