You have to take a look at this. I found this on urbanvelo.org. Someone thought it would be a good idea to weld a couple of bikes to a roller coaster car. The source site calls it a green coaster. It looks like a lawsuit waiting to happen, though the pink basket is a nice touch. You'll probably die if you fall, which might be a good quick way to go given the state of hospitalization in Japan (urbanvelo).