Yeah, Europe runs on 220V. Usually if you check on the back of the power adaptor for devices like MP3 players and cellphones it will tell you the voltages it can accept, and if it says something like 100-240V then all you need is a plug adaptor. If not then you'll need a proper voltage converter as has already been mentioned on this thread. Make sure any converter you buy can handle the current load you're going to put on it, e.g. a cheapo one may be fine for stuff like your toothbrush or shaver but for example if you were going to bring over a console like an Xbox or something it wouldn't be sufficient.