This deal has ended.
Buy.com has the Cavalry 500gb USB 2.0 External Hard Drive for only $127.95 after a $17 mail-in rebate valid through 3/26. Plus, shipping is free and there is no sales tax (except CA, MA, MD, TN). At $0.25 per gigabyte, this is as low as it gets for external storage. Also of note: Buy.com has a new and very-rare $5 off $50 coupon valid in all stores for new customers through 3/31 and new Google Checkout users can get a $10 off discount for signing up (but you can't get both).