Actually, there are widely used standards even for mains power: http://en.wikipedia.org/wiki/IEC_connector http://en.wikipedia.org/wiki/IEC_connector C15/16 a

Actually, there are widely used standards even for mains power: http://en.wikipedia.org/wiki/IEC_connector http://en.wikipedia.org/wiki/IEC_connector C15/16 are widespread for grounded, C7/8 for non-grounded all over the world. I even use C16 distributers with C15/16 extensions to the devices at home (having moved repeatedly within Europe, this ended up being easier), but those are comparatively rare. The article actually lumps almost all of Europe into one, which is an oversimplification. Leaving aside the Swiss and Italian systems, there are 2 at least types of grounded sockets in continental Europe, the Schuko and the CEE 7/5 (fr be cz pl, sk). Both are round with round and symmetrically placed neutral and live contacts, but the former has 2 springs at the side for ground, whereas the latter has a male ground prong. Luckily the plugs can be made to fit both (CEE 7/7), but that doesn't mean that all are. You may not have to worry about borders while travelling in Europe, but you still have to worry about plugs & sockets.