Best Buy offers the Toshiba Canvio Basics 500GB Portable USB 3.0 External Hard Drive, model no. HDTB105XK3AA, for $49.99 with free shipping ($0.10/GB). (Amazon also offers it for the same price.) That's $10 less than the lowest total price we could find for any 500GB USB 3.0 portable hard drive today, although we saw it for $10 less on Thanksgiving Day. (It's a current price low for this model by $10.) It runs at 5400 rpm and features an 8MB cache.