Facebook/Myspace/ Social Networking are one of the worst things that has ever happened to humanity. The information overload of crap we don't and shouldn't know combined with the speed at which it disseminates is going to change for the worse our social/emotional framework.
While useful to say, talk to people you've met while travelling abroad or on exchange, or those that have moved away, I really don't need to see pictures of my ex girlfriend posted on facebook about what guy she was actually with the day she was "busy" and broke up with me. Nor how great this 'friend' of mine thinks about my other ex who he took to a dinner and a movie while She and I were supposedly dating. (24 hours after this we were not because she 'didn't feel the same way about me anymore')
Combine those things with the fact that Facebook has spawned websites such as the dirty where people continuously gossip and talk shit to each other more than with just the former, get in fights and arrested over it, etc.
Yeah, I'd rather live without it. I have a cell phone with text messaging and calling, and Email if I paid for it.