If you have a Mac Pro (which have yet to be updated with Thunderbolt) and a USB 3.0 hard drive, you can take advantage of USB 3.0 speeds by installing HighPoint's new RocketU Quad USB 3.0 PCI-E card. The RocketU features four USB 3.0 ports, with each port rated at 5Gbps (USB 2.0 is rated at 480Mbps). The RocketU can be used with USB 2.0 drives, but there isn't any added speed benefit.
You can connect four different hard drives to each port of the RocketU, and each drive will appear on your desktop. But the RocketU also has a RAID controller, and you can configure up to four devices as a RAID 0, 1, 5, or 10 array. HighPoint includes web-based RAID management software.
The RocketU is $125.
Thunderbolt, the new connection technology that Apple first implemented in the MacBook Pro in February, promises fast data transfers. Thunderbolt hard drives, however, have been slow to market--six months later, we're still waiting for a flood of Thunderbolt storage devices. There are Promise's Pegasus R4 and R6 RAID arrays, and the $49 Apple Thunderbolt cable, and nothing else (there's also Apple's Thunderbolt Display if you consider non-storage devices). With USB 3.0 now standard equipment on hard drives and USB 2.0 being standard equipment on Macs, Thunderbolt is the only way to take advantage of USB 3.0's speed, but there's not even a USB 3.0-to-Thunderbolt adapter available.
Owners of the 17-inch MacBook Pro can get a USB 3.0 ExpressCard, such as the one from LaCie. As for users of the iMac, Mac mini, 13-inch MacBook Pro, 15-inch MacBook Pro, and MacBook Air who want to take advantage of USB 3.0 speeds, the wait for adapters continues.