I deactivated my Facebook around New Year time after getting ever increasingly annoyed at family and friends on there, Like Stant says seeing what people had for breakfast others constantly moaning or airing their dirty laundry on it for everyone to see. Too others trying to hard to convince others they live the perfect life. I actually blame facebook for the increased amount of Mongs that use the internet now too, the people that wouldn't have used the internet that much came on for facebook and discovered other places that they could use to annoy people :)
I also think it does a lot more harm to people then good. Well the bad things far out weight the good by miles. Just before i'd came off it I even had a mate of mine's Missus message me asking if I knew a certain person as he was going around saying me and her had been getting our groove on. Just point out I hadn't and didn't even know the guy, I'm guessing he just looked down her freinds list and picked people out but could have caused trouble as easy as that.
I'd rather meet new friends on here and swap phone numbers least that way I either have to go out and meet up or pick my phone up :D
I might go back on at some point,I've even thought of making another account up and just adding a select few