I have a Lacie 2TB which came with several adapters. I can use it in North America, Europe, and there are 3 other adapters I don't even recognize
Edit: it's a larger one, i.e. with power adapter.
It may be simpler indeed to get a WD My Passport or a LaCie Rikiki or whatever Seagate or Toshiba have to offer - smaller drives that take all the power from USB. They're easier to carry around too.