After years and years of successfully avoiding Myspace, I was forced by my university to create a Facebook page upon entering college. Since I graduated I have often wanted to delete it--Facebook has caused more than a few problems for me, especially with regards to relationships/girlfriends. However, I never bring myself to do it because it has allowed me to keep in touch with people that I will otherwise probably never speak to again (people I actually like, but who live in other countries or on the other side of the US, etc.)
In the end I decided to compromise and limit it to the fullest extent. I don't have a wall and the only pictures anyone can see of me are my profile pictures and the ones I put up (mostly landscapes from hiking trips or mountain climbing etc, none of me fucked up and half naked like there used to be). Basically it is just a page with my contact information. I never go on unless I get an email telling me I have a message or some shit. It works out pretty well.