Sphero

Sphero is part robot, part ball, and a whole lot of fun.
Actually, it's a gadget, a toy, a controller, colorful ball, and a cat toy all rolled up in one.

In short, Sphero is a cute little remote control ball which you control via apps on either your iPhone or Android.

Here's their promo video where you can see some of the cool things you can do with a Sphero:

Pretty impresssive stuff ah? It even works in water!

It’s the first robotic ball gaming device that you control with a tilt, touch, or swing from your smartphone or tablet. You can even use Sphero as a controller for on-screen gameplay. Sphero delivers a unique mixed-reality experience with single and multi-player apps that let you engage in the virtual world and play in the real one.

There are a bunch of different apps you can use with Sphero, here are some in action:

Sphero gives you over an hour of full throttle play and even charges with cable-free induction (it has a cute docking station that you just plop the ball into and it charges).

Even President Obama had a good time playing with and controlling Sphero. You can see him here playing around with it and actually saying "Excuse me, give me some space to drive my ball.":

Sphero costs $130 and you can order it online today (from their site or ThinkGeek).