Linus Ã…kesson made this amazing robot to clean out his kitchen chimney. In the end, the chimney was clean, and the kitchen fan worked once again.
The claw hangs from a long cable, providing power and a control signal to the servo. At the other end of the cable is a plastic box with a power switch and a knob (actually a cog-wheel) on it. By turning the knob, you make the claw open and close. Inside the plastic box are batteries and a programmable micro controller, whose job it was to continuously figure out what position the knob was in, and report this down the line to the servo.
More about the Chimney claw project.