This deal has ended.
Buy.com has the Cavalry 500GB USB 2.0 External Hard Drive priced at $89.99 after a $20 mail-in rebate (expires 4/14). Shipping is free and there is no sales tax (except CA, MA, MD, TN). $0.18 per gigabyte is a great deal on external storage, and this particular drive is compatible with either Mac or PC. Plus, new Google Checkout users can get an additional $10 discount for signing up.