Western Digital Elements 500GB 2.5" USB Portable Hard Drive for $64.79 shipped after coupon code JPKNV2V$VBV?T5.  Here is a screenshot for your reference.  Remember to select free upgrade to 2nd business-day delivery.  Note that this 2.5" portable drive does not require a separate power supply like most external drives.  It is also smaller, making it more convenient to carry around.  If asked during checkout, simply use your name as the business name.  Most places have it for about $98.