Iomega eGo II 500GB USB 2.0 Portable External Drive for $64.00 shipped.  Scroll down a bit to see it near the bottom of the page as shown here.  Valid on 3/16 only and while supplies last.  Here is a screenshot for reference.  This portable drive is USB powered and does not require an external power supply.  It is also smaller than most external drives, making it more convenient to carry around.  It normally goes for over $100.