http://www.electricsupercharger.com/

here's another one. After reading a little about it they use the electric superchargers more like nitrous to where the turn it on just like you were using nitrous to boost your HP. From what I've read so far it drains your battery fast so it wouldn't be on like a normal supercharger and they only provide a constant pressure rather than more or less depending on your engine's RPM. All in all a cheap nitrous like effect that you don't have to refill. It would be nice to develop an electronic supercharger that maintains PSI with your RPM vs. one constant PSI.