a human you would probably use a box, as a human shape is pretty box shaped overall anyway. This is a prototype form of a platform game that I did quite a while ago, it shows how to do walking up sloped plains, sliding collision at any angle, between several plains at the same time, jumping and also a crappy climbing up walls thing that didn't work very well. There are some bugs in the code (you suddenly jump through walls when you dont want to). Feel free to use it all you want.
Why the hell'd you ask me for crying out loud!?!
Athelon XP 1400 Plus - Nvidia Geforce MX400 - 256mb RAM