Tech question

Question for the tech types and hardware groupies on my flist:

I’m looking for an ultraportable hard drive, USB-powered, at least 40GB, but not more than 80GB or so. I’ve found some possibilities, such as the Edge DiskGO! and the SimpleTech STI-USB25. I’m not familiar with these brands, and not confident I’m going to get a quality product. Of course, I’m also cheap and would like to pay <$100 for this. Anyone have any experience with this category of device? Recommendations?