Western Digital offers its Western Digital 500GB My Passport 2.5" Portable USB 3.0 External Hard Drive in Silver, model no. WDBKXH5000ASL-NESN, for $44.99 plus $2.99 for shipping. That's the lowest total price we could find by $12, although we saw it for $9 less last month. It features automatic, continuous backup and password protection.