Well, I was on the phone with one of my friends when out of the blue, this I idea came to me. I'm sure all of you are aware of the diamagnetic property of water (and everything else I guess) which is repelled by both poles. If the field could be concentrated on one side of a 'rotor' or linear runner by keeping the water away from some areas, and have a flux altering steel sleeve, could it potentially have the energy to move in one direction/in a circle? Here's a drawing to help explain what I was thinking...
http://nullium.fileave.com/23.jpg
Any ideas/thoughts/criticisms? Also, the yellow sleeve would be to keep the water free from most of the flux at the front end... Or maybe some Bismuth pieces in the water could make it 'more' diamagnetic?