My backup processes are described here.

My main use of this portable bus-powered hard drive is for backup when travelling. If I am shooting enough to need to re-use cards, I want to have my photos stored in more than one place. A laptop is my primary storage, and this drive is the second.

The Lacie Mobile Drive is a USB2 external hard drive that differs from a standard external drive in a couple of ways. First, it's significantly smaller and lighter (you can see the size of it from the sunglasses). Second, it is bus-powered, meaning you don't need a mains adapter: it draws its power from the USB port. Carry the drive and a normal USB to mini-USB cable and you're set.

It is also sufficiently small to be carried in a pocket, so in the worst-case scenario of my camera backpack being stolen, all the photos taken prior to that day will at least be safe.

This particular model is 100Gb. Admittedly that's a bit OTT for field backup of photos (storing over 5,000 D200 NEFs), but storage capacity is cheap, and it doubles as a means of transporting large files like Tivo programming.