Zorbs!

Basically, they are human hamster balls -- and you can use them to run into each other with or roll down hills in.

This video shows people being chased and run over by the Zorb balls.

While it is not injury free, it looks like so much fun.

Originally created by a New Zealand company, you can new buy off-brand inflatable Zorb balls on eBay for about $200. Get one today and protect your kids, run over your friends or float on water.