While it’s true that not all robots have to move around to be cool, it’s also true that a robot with the freedom of movement is a lot more exciting and versatile than a stationary robot. To give you robot some movement, the 65mm by 25mm Robot Wheels are great, and works with the 3-6V DC Geared Robot Motor. These wheels are sold as single units and are designed to be controlled via geared motors and an Arduino Board or similar development platform, allowing Makers to build robots that can move around freely.