CF cards are not the only thing you have to worry about. On a short trip (2-3 days), you can get by with a portable harddisk device. On a longer trip (say more than a week), you might want to consider lugging a laptop around as well. An X-Drive should not be your only backup. There's no confirmation, and one drop or accident could wipe out thousands of pictures.
You also have to remember that the Xdrive will only last about 3-4GB of copying before going flat. That means if you're without a power source (eg trekking), even if you Xdrive has a 60GB hdd, you effectively only get 4 gb on the move.