Roll your own DDR

There's a post on BoingBoing today about a free and open-source alternative to Dance Dance Revolution called StepMania that's brewing:

Two dance pads plus a USB controller are about $30 (shipping included) on eBay and they work great with Stepmania... even on my Mac.

Since we're interested in personal motion games, this might be a great thing to look into. More importantly, since it's open source, we could learn from the code for reading the dance mat input in order to create our own personal motion games.