About these plugs:
[Linked Image from 320036920636.bei.t-online.de]
It looks like you can plug all of them in 2 different ways. The ground would stay the ground, but the hot and neutral could be flipped. I suppose the equipment is requred to be designed to expect the "neutral" might in fact be hot? Which would also mean that the equipment won't mind being powered in the USA by our centertapped grounded 240V system (assume the equipment doesn't care about line frequency, 50 vs 60Hz).