Review (5/5): This is the one
Forget all those silly plug in rechargeable stands that will just clutter up your bathroom, and built in batteries that will wear out. This, plus some NiMH AAs, is the way to go. You can travel with it and not worry about it. Just throw it in your bag, the car, etc. It's cheap and works great.
btw, if you like magnets, don't forget to harvest the cool magnets off the end of the brush head when you replace it, they are awesomely powerful! They're just glued on.