Makey Makey can make anything into a keyboard. The device transforms surfaces with a touch-sensitive computer control. It's basically a hardware interface that uses clips that attach to items, making them into keys. Each set has a circuit board that hooks up into your PC with a USB cord and alligator clips. The only requirement for the objects you use is that they have to be able to conduct a little bit of electricity. It is available for $59.99 and can be bought here when in stock.
[via CoolThings]