Yep, I do have a facebook account.
Mostly, I've been trying to keep my list of facebook friends to people I know in the real world (outside of facebook).
If you sent me a friend request and I didn't respond-- well, I probably didn't see it; facebook has a listing of who sent friend requests, but I turned off the notification e-mails and I don't check the friends-request list very often. So, if you do want to friend me on facebook, send me a note to remind me who you are and how I know you. (And please assume I have a very bad memory for names-- I probably will remember who you are once you jog my memory, but I do need context before my mental rolodex can associate a name with a face kicks in).