Sphero by Orbotix

Sphero by Orbotix

Part ball. Part robot. All fun.
   Sphero by Orbotix is the world's first robotic ball and gaming device that you control with a tilt, touch, or swing on your iPhone, iPad, or iPod touch.* Easily connect to Sphero via Bluetooth, then dive into unique, mixed-reality gameplay using fun and challenging built-for-Sphero apps.

•     Control Sphero wirelessly from iOS devices
•     Use Sphero as a controller for on-screen games
•     Intuitive controls are easy for all ages to learn
•     Download free Sphero apps like Drive and Golf
•     Use on wood or tile floors, sidewalks, carpet

Source - http://store.apple.com/us/product/