I came across this video the other day.
If you don't want to watch it, it shows a guy using a roller suit (yes, a suit with wheels) going down some crazy hills in the Swiss Alps. He is going insanely fast. My favorite part is where he passes the motorbike. I just don't understand how he steers. One wrong move and he will smoke a barrier.
This video reminded me of another other crazy sport (which I may have blogged about earlier)