Seagate STAX1000101 Expansion 1TB USB 3.0 Portable Hard Drive for $59.99 shipped after code EMCWWWR52. Here is a screenshot for reference. This portable USB drive is USB powered so there is no need to carry an AC adapter. It is also one of the thinnest portable hard drives on the market at 0.61″. Most places have it for about $79.