I was watching National Geographic channel and they had a documentary on showing people doing "suspensions" (hanging from hooks pierced in the skin). It is very, very interesting but at first I found it very hard to look at. The question that came to my mind is: is it supposed to be painful? Is that one of the reasons why you would do it? (Why not just wear a harness instead?) Why in god's name would you do that to yourself? I hope to try it someday.