This deal has ended.
Newegg.com has this Seagate 500GB USB 3.0 Portable Hard Drive for $49.99 with free shipping, the lowest price we could find by $17. This hard drive is about the size of a notecard and weighs just under 10oz, so it is highly portable. Since it features USB 3.0 technology, data transfers are up to 10x faster. It comes with a 2 year warranty. Sales tax is only charged in CA, NJ, and TN.