If you take a computer designed for 120V AC to Europe, chances are its power adapter will be dual-voltage: get a simple plug adapter, and you can just plug it into a 240V outlet. But there can be weird side effects: - I once had a laptop that felt sort of weirdly charged (the hair on my hands would stand on end when I touched it, and sometimes I felt a faint continuous electrical shock through my wrists when they rested on the laptop body). - My 2nd generation ipod nano feels "buzzy" if you run your fingers over it when it's plugged into my netbook, when the netbook is plugged into the wall on a 240V circuit. Disconnecting the netbook from the wall makes the buzzy feeling go away. - If I firmly grip the ipod with one hand and stroke it with the other, it does not feel buzzy (presumably because it's grounded to me). - My kindle paperwhite's touchscreen goes haywire in the same setup -- it behaves as if I'm doing all kinds of crazy multi-touches. - I can solve the Kindle problem by plugging my ipod charging cable into another USB port on the netbook, and pinching the exposed metal part with my fingers -- if I then touch the Kindle with my other hand, it behaves normally.