Modular Robotics

Cubelets are magnetic blocks that can be snapped together to make an endless variety of robots with no programming and no wires.  You can build robots that drive around on a tabletop, respond to light, sound, and temperature, and have suprinsingly lifelike behavior.  Each cubelet cube in the kit has different equipment on board and a different default behavior.

http://www.modrobotics.com/