I end up having to buy these a lot for work, so I'll just throw in my two cents that I've had a LOT of the Seagate ones go bad on me, and their replacement policy during warranty is pretty draconian (as in you have to pay them to send you the box that they want you to send it back to them in - and if you don't, you void the warranty). I was going to recommend Maxtor, but it seems like they and Seagate have now combined into one company (dammit!).

This Toshiba is $50 for 320GB - it looks nice and portable, too. http://www.newegg.com/Product/Product.aspx?Item=N82E16822149215

-- Cel