Ultra portable hard drives with USB interfaces there are plenty of, but ultra portable hard drives with firewire interfaces are scarce. Which is a shame because even though USB is more widely available, firewire transfer speeds tend to be more consistently fast and reliable than USB 2.0. The Aegis Mini Ultra is a tiny 3.5 oz hard drive available in 30GB, 60GB, and 80Gb capacities, each with a firewire or usb interface. The device is bus powered so that no AC adapter is required and the cable is integrated so there is no need to carry around a chord with you. At $249 for the 80GB Firewire version, the Aegis Mini Ultra is no bargain but it is one of a kind. It also comes with back up software, encryption software and synchronizing software, an extension cable and a neoprene travel pouch so you are getting a decent value overall.