Get from Amazon.com : http://www.amazon.com/gp/product/B004LB4MZS?tag=hawaiianlegac-20

Seagate FreeAgent GoFlex Desk 2 TB FireWire 800 USB 2.0 External Hard Drive for Mac STBC2000100

Compatible with Time Machine software
FireWire 800 or USB 20 plug-and-play
Use the same drive interchangeably on both Mac and PC computers
Upgradeable to USB 30
FireWire 800 USB 20 desktop adapter with capacity gauge display
Offers both vertical and horizontal drive orientation