The original Sphero was an interesting idea, but it was a bit delicate and underpowered. Sphero 2.0 might be worth some consideration, though. Orbotix has made the new Sphero twice as fast (about 7 ft per second) and packed in a bunch of LEDs to make it three times brighter than Sphero 1.0. The company is also dropping an updated driving app to go with the new ball.
To show off the increased speed and acceleration, Orbotix is including two ramps in the box so you can catch some air with Sphero 2.0.