I've done one of them. In fact, I think there are only two available in youtube; too few for such a successful game. It would be nice to have more since, at least for me, youtube is a nice reference when I'm trying to find more about a game or any software/hardware.
http://www.hyperionics.com
Here you can download Hypercam. It's a shareware, but all the functions are available on the free download version. You'll get a message on the top left corner of the screen when recording. Just select a bigger area in that direction and then cut it of when editing or let it there if it don't bother you.