From the Toys section:
Today only, HP Home & Home Office Store offers the HP 500GB 2.5" Portable USB 2.0 External Hard Drive, model no. RF863AA, for $93.74. Coupon code "AC1874" cuts it to $74.99. With free shipping ($0.15/GB), that's the lowest total price we could find by $9. Sales tax is added where applicable. This 7200 rpm USB hard drive can be plopped in a MacBook with the old HDD being put into the USB 2.0 enclosure.. It also works as an external drive for any PC. It is the lowest price we've ever seen for a 500GB 7200RPM drive.