Oleg put together this pretty neat robotic arm that he can control using a standard USB mouse. He used a Lynxmotion robotic arm with a wrist upgrade, an Arduino as the brain, a USB Host shield in order to interface a regular computer mouse, and a custom made servo motor controller.

This is a rather clever design and, as shown in the video below, all the degrees of freedom of the arm can be controlled by combining the motion of the mouse and the scroll wheel, and the clicking of the mouse buttons.

Via Hack a Day (via Circuits@Home)