The Guardian MAXimus is a hard drive enclosure that sports FireWire 800 & 400, USB 3.0 & eSATA. But the real trick is inside. The MAXimus supports hardware RAID-1, which mirrors the two drives to protect against data loss.
It comes with a 3-year warranty, and the option to pack as much as 4 TB of storage in the thin black case. If you want to add your own drives, the case is just $117.
I have one with 1.5 TB drives in it for my iTunes storage at home, and it has run like a top for years. While RAID shouldn’t be used without a backup, if you want a little piece of mind and some major storage, you owe it to yourself to check this out.