Afraid I don't quite understand. You want it so when you wave your hand in front of the case it shuts down or powers on? Could be hazardous to your gaming if you have pets or keep the case under your desk, nothing like playing CS and getting fragged because your dog walked in front of your case.
If your going for a simply lit power button. Shouldn't be too hard to do, find a translucent or clear piece of plastic and shape it down to fit in place of your old power button and have a red LED placed close to the button.
~Vash~