From 500GB to 3TB, the FireWire 800 and USB 2.0 Seagate GoFlex Desk for Mac features a desktop version of Seagate’s interchangeable connector system. The drives work on both Mac OS X and Windows so no worrying about incompatible file systems and the like, though you'll need to download a Windows driver in order to access the drive on a Windows machine. It's fast too, running over FireWire 800. You can boost the speed still by opting for a USB 3.0 dock; FireWire and USB 2.0 are the right choice for most of us until USB 3.0 really starts to make inroads.