Basically I took AZ's spinbike design and added bumpers. The result? Bumper cars that you can ride anywhere. These are brutal and an absolute hit. I presented them at the Corinbank festival where I am in New South Wales but I hope to turn it into a legitimate festival event. We've already started to think up sports you can play: Last one bumped out of a circle, hockey with a shopping cart puck, etc etc.
Remove the "t" in the filename to get a closer look. I'll get some video up soon.