I recently joined Facebook grudgingly at the request of a long distance friend who rarely uses e-mail. I used a separate e-mail address and set my privacy to the max. My biggest fear is that it will steal more of my time as I already spend too much time on the PC--mostly on quilt-related stuff. So, I decided that I will only check on it every few days, rather than everyday, and not use it as a substitute for e-mail.
My adult son asked me to be his Facebook friend, but I now get a little too much information about him--nothing bad, but I want to respect his privacy among his friends.