I took the plunge and severed ties with Facebook. There were many reasons for this decision. Mostly, it is a major time-sucker. I had over 300 friends and checking their sometimes multiple statuses even just once a day took a large chunk of time, not to mention all the fan pages. I had also got sucked into some of the games, which took even more time. Also, Facebook has no respect for anyone's privacy, and their "privacy" policies are only to cover their own butts. Plus, every time they would make a change, everything would default to a public option. Not cool.
I am joined in my leaving by my mother and brother. My husband remains on, because he is addicted to technology, but I love him anyway. I know I also have several friends considering the move also.
I'm going to link to a couple articles I found influential in my decision, and helpful in my attempts to complete it.
How to Delete Your Facebook Account (because they don't make it easy)
10 Reasons to Quit Facebook
And a funny video about how absurd Facebook can be.