doesnt exactly answer your question, but you might find this the be a nice idea (straight out of popular science)
instead of buying an external hard drive, just make your own. you can get a lot more storeage for a lot less money, and its incredibly easy:
1. Western Digital 300GB hard drive ($70 @ best buy)
2. Cp tech. aluminum USB 2.0 enclosure ($15)
all you have to do attach the data and power cables inside of the case to the hard drive, screw the hard drive to the back bracket, and insert the whole thing into the enclosure. Then you just have to screw it closed and you've got a 300GB external hard drive for $85 and 15 minuets of your time.