The Power Mac G4 Cube was not a success in its day, but a very good machine for making crazy games. Proof of this was the following experiment, produced by Thinkingbricks, which gave him wheels similar to those of LEGO robots and a red LED on the Ma, in addition to remote control via Bluetooth:
(youtube) http://www.youtube.com/watch?v=icC1X5qWmkY (/ youtube)
The work, which is quite complicated to do due to the procedures that must be taken with the base of the Power Mac, gave it a very particular look, but at the same time it did not hinder the machine's operation at all. All control of the movements of the pussy done through a Bluetooth control.
There are no step-by-step instructions for reproducing the exploit, but the article produced by its creators at least gives a lot of information for those who want to venture out. Now, have you made or would you make such a change on a Mac?