I just wanted to report that I have been using the Fujitsu RE25U300J 300GB HD with no problems. It loads pretty quickly. It comes with a Y cable for extra power from a second USB which I am plugging to the cigarette lighter with a Kensington power adapter.
http://www.newegg.com/Product/Produc...82E16822116042
http://www.circuitcity.com/ssm/Kensi...oductDetail.do