I didn't have much to do at work today and threw this together pretty quick:
Basically if you can't tell from the picture it essentially screws onto a tripod and then your camera would screw on top of it. The motor in the middle would be able to rotate 360 degrees at a programmable federate, adjustable by a knob or whatever algorithm you wanna run. It would give a smooth rotation as long as you don't load the motor to bad.
Its like $10 worth of components and then electronics would probably be another $10, therefor I could probably sell it for pretty cheap.