Sphero is a remote-controlled sphere about the size of a baseball that can be steered around at speeds of up to three feet per second using an iPhone or iPad app. Spinning, weighted components inside the ball let it roll around and change direction.
Sphero is made by Orbotix, based in Boulder, Colorado. It contains a Bluetooth receiver, an LED light, a compass, a gyroscope, and accelerometers. Orbotix has released an application programming interface that lets outside developers create apps for the ball. This should result in some novel new Sphero behaviors and games.