While I've met around two-thirds of my friendslist, I wouldn't say that I know a lot of you very well (mainly because for a lot of us, the average conversation has consisted of saying "hello!" and waving briefly while wandering around at a convention).
So, the idea is this: Comment, and ask me one thing about me that you think you should know, but don't - the sort of thing you'd be surprised to find out only after knowing me for five years, say.
Then, tell me one thing about yourself that you'd expect everyone™ to know, but which I might not.