This deal has ended.
Through 12/19, Buy.com has the 1TB Cavalry External Hard Drive (model CAUM3701T0) on sale for $99.99 after this $20 mail-in rebate. Checkout using PayPal for an additional $15 discount, lowering the price to just $84.99, the lowest we've ever seen for this. Plus, delivery is free and there is no sales tax (except CA, MA, MD, NY, TN). This features one-touch backup and you're paying less than $0.09 per gig.