Here is a low-cost solution to backup your images when no computer is available.
The Icy Box contains a standard 3.5" IDE HDD (also called Serial ATA). It has a USB 2.0 port (optional firewire is a bit more expensive). Connect the Icy Box to the Syncbox ( http://www.icintracom.com/content/syncboxpage.html) which acts as an in-between for the camera and icy box USB cables. Press the button once and the syncbox is switched ON. Press the button a second time and the data transfer starts. To transfer some 190 files from a Olympus C-770 512MB card takes a bit more than 13 mins. The syncbox is only a USB1.1 device so it takes some time. You know when data transfer takes place because the red light on the syncbox (and the camera) flickers.
The whole setup weights in at 1.5 kg.