[sanddrag]

Well, you can get a two AAA battery holder and a toggle switch (or other kind of switch) from Radio Shack. For simplicity, get a toggle switch with only two terminals, kind of like this. This is called an SPST switch, Single Pole, Single Throw.

Then, take one wire from the battery holder, and connect it to one terminal of the switch. Take the other wire from the battery holder and connect it to one wire of the motor. Then take the other wire from the motor, and connect it to the other terminal on the switch. That's all there is to it. You are basically hooking the two motor wires to the two battery pack wires with a switch to "break" the connection along one of them. In this application, it doesn't matter what color goes where. If the motor is running "backwards" swap the wires.