I guess I'm one of a few people who don't use Facebook like a teenager.
I've got an account there and I'm happy with. Occasionally make a wall post, occasionally upload a photo or album, occasionally check out my friends new stuff who have moved away. I spend longer browsing on MR than I do on Facebook and Twitter combined, and even that is just 30 mins a day.
A bit of a self control and hiding people who you want to know, but can't put up with their BS, is all you need.
Personally I love it. I can keep in touch with family, fans, colleagues. I've got a good set of privacy and group filters going so neither work or family stuff mix. Can't fault it - just the 3rd party apps.