Toshiba 400GB 2.5″ USB 2.0 Portable Hard Drive for $53.99 after code 7LXC0FZZR54P3X. Remember to select free upgrade to next-business day delivery. Here is a screenshot for your reference. If asked, simply use your name as the business name during checkout. It does not require a separate power supply like most external hard drives. It is also smaller and lighter, making it much more convenient to carry around. Most places have it for about $89.
Originally posted earlier, this post has been revised and a coupon code has been added.