How much tech can you pack in a 3 inch sphere? Start with a sensor network – multi-axis rate gyro and accelerometer – fused together with the same kind of math that took Apollo to the Moon. Power it with lithium polymer batteries that are inductively recharged through the shell and add a Bluetooth-based command and control data link. Finally, mix in over-the-air firmware updates and internally sandboxed language extensions and you have a true robot that is an intelligent component of a smartphone app-based gaming, learning, and human-machine interaction system. Driving Sphero from the central app is just the start. An open API for iOS and Android invites developers around the world to dive right in…Oh, and Sphero is just fun.

http://www.gosphero.com/

That does look fun, but I want it to go a little faster.