Then I remembered, Chop!, that you don't have plastic wheels.........

I've just read that the 120's aren't as bright as the 100's. Is that your observation? I can't find a decent pic' of how they're mounted as I see there's a folder specific version.

Here's another power source:

http://www.treehugger.com/files/2006...ble_whammy.php

of which there's plenty around here :-)