I found a link to a really easy to make homopolar motor using a battery, a wire, a screw, and a strong nickel plated magnet.
You can check out the evilmadscientist site for a cool video and explanation. He has some other cool experiments as well with one that moves water.
So I tried it out for myself but I used one AA rechargeable battery and a nail. I used a nail because I didnt have a screw with a sharp point.
Here is what it looked like.
I was even able to run the motor with one hand. The wire I used was stiff enough to keep touching the magnet.