After wishing my Black and Decker "Mouse" sander was smaller, I considered doing the same thing at one point. Never got around to it but may have to revisit the project if I can pick up an el cheapo toothbrush.
Picked up the parts the other day, but just got around to putting it together. Amazing little tool. I tested it out on some Bondo Glazing and Spot Putty I used to fill the spirals on my Airborne Surveillance Missile. Worked fantastic, my new favorite tool.