The Wall-hop (wall hax, etc.) is a totally n00b manuver, which is why I didn't post this a while ago. NEVER use this move in a serious game. Fair warning: if you Wall-hop during a serious game, you may be taking a chance on getting kicked/bant.
Anyways, the wall-hop is fun to try if you're bored, and even more fun when executed successfully. I was going to record myself doing the Wall-hop, but I found a clip on YouTube of someone else doing it. Well, just watch the video:
http://www.youtube.com/watch?v=qWDEfeyWY4k