Facebook II

A few weeks ago, we at the Spin Cycle blogged about Facebook and/or Twittering and all the "IM"-ing (which will soon be a new verb) going on these days. From a conversation I had today with a friend, my follow-up question is this: What's appropriate and what's not to post on Facebook? (I'll stick just to that since I don't Twitter and I don't, normally, send text messages.)
Obviously, it's an individual decision. Such as--Does this picture of me in my bathing suit look too suggestive, or too Mary Poppins? And, how people react to various posts and pictures is out of that individual's control. I've only been on "FB" a short while (six months?) and some of what I read are beyond the pale. (Or is that just my pale?) What do you think, Internet? What's OK and what's not?