A cute Arduino powered spherical quadruped robot has been created by Gregory Leveque, using an Arduino Nano, along with a 16-channel servo driver board. Technology included in the small robot include ...

We’re all pretty well-acquainted with the obstacle avoiding robot. These little inventions use a proximity sensor to detect an object in front of the robot, then circumvent the object accordingly.

So you've already outgrown Arduino's most beginner-friendly board, the Uno, and are looking to move on to bigger, more exciting projects. In that case, the Nano family might just be what you need.