MaKey MaKey: An Invention Kit for Everyone
The MaKey MaKey is basically a USB keyboard and mouse controller. You plug one end of your alligator clips and jumper wires into the circuit board and then connect the other end to a conductive surface. Then use your imagination to build all sorts of remote controls in order to interact with your computer. It's fun for kids of all ages.
The MaKey MaKey Kickstarter project has one week left to go and is already well over funded. I'm in as a backer. (Found by David Sparks.)