The Laser Dance Matrix is the brainchild of Applied Sciences. It's a DDR (Dance Dance Revolution)
matrix for getting down up, up, right, back style. But instead of relying on pressure sensitivity as most pads do, the Laser Dance Matrix senses foot position based upon breaking the proper laser beams (we're assuming in the correct places, though you might be able to cheat). Dancing occurs right on the floor.
The prototype is USB compatible, though it requires a separate power source for all those badass, entirely invisible laser beams. We wish that Xbox 360 wasn't so hard on third party manufacturers, otherwise we'd be happy to trade the Matrix for their one supported break-your-neck-plastic style pad.
Hit the link to vote on whether or not Applied Sciences should sell the unit. Click "yes" and that we want the preassembled units. Because I'm lazier than I am cheap.