Thats a really great idea. I tested it with a usb supply to the arduino but I didnt realise the max amp output from a pc usb is only 0.5A. I will try it now with a wall wart. If I power the arduino with a 5V 2.0A wall wart and then power the rest of the circuit through the 5V pin from the arduino will it be able to supply the whole circuit? I know there are power limitations on the arduino pins, just not exactly sure what the limitations are.