I'm looking for an external hard drive with a storage capacity of more than 200 GB. All external hard drives which I've found so far that match these specifications use a separate AC adapter for power. I'm only interested in models which are fed power through an USB port. I have seen a 250 GB one in action before, but I cannot remember its brand, nor has Google been of any avail.

Any help would be greatly appreciated!

"Stephen Wolfram is the creator of Mathematica and is widely regarded as the most important innovator in scientific and technical computing today." - Stephen Wolfram