I have an account, sure, back from '05 when I started college. I log in so infrequently that I often get emails from facebook along the lines of "you haven't logged in in 3 months. We think you should come back because...".
I never got into that whole thing about walls and public conversations and public comments. I'm far too self-conscious (and I judge far too harshly). The whole thing just drives me nuts. Some of my best friends and I are not even facebook friends.