This sport is just one step away from greatness. They are calling it vertical soccer. You strap two dudes to a harness and the play with a hanging ball on the side of a building. The only thing is there isn't really a penalty for losing. I suggest the put goals up and rig them to the latches that are holding on the harness. Then when the player scores a goal he gets the pleasure of watching his opponent plummet to the street below.