After successfully scaling my geared batcopter down to its original size, I decided all it was missing was a motor. After watching JMEMantzel DIY lego motor video I took a quick peek at the spare RC motors I had. One of them was just the right size. So I drilled a hole in a lego axle glued it to the motor, and then did a simple test like in JME's tutorial. It worked great on 1.5 volts so installed it into the Batman's X1 Helicopter. You can see the final results here
If lego offered some smaller motor options, I wouldn't have to resort to drilling and glueing:) It is sort of too bad that there isn't more crossover between the technic line and the Lego theme sets. Time for lego to make some plug and play options for motors, lights etc. for the minifig scale. Hope some others try the homebrew motors :)