Any clue if there's a version for german plugs with ground pins (schutzkontaktstecker) for the duckhead? I like not having an additional cable going from the AC to the outlet, but not having the computer connected to ground means that there are some problems, including static noise on headphones, and this "rubbing" sensation.
The transformer end is a standard IEC connector (C5 I think, I don't have a Mac). You can use any appropriate cable, e.g. a 30cm one if you can find it.
I doubt there's one that fits on the transformer. The UK socket will only accept a plug with an earth pin as one of the safety features, so there's no opportunity to cut cost here.
