An extreme urban sport requiring no equipment or tools other than your own dexterity. "Spidermanning" is the best word I can think of for it, but the official term is "Parkour" (thanks arn). More on Parkour here on LF
I must admit it has a certain appeal, but that's probably because only an idiot would consider doing this.
Thanks, zf. Opens to embedded wmv with music. NSF Anyone without adamantium knees