I try to take a laptop when I'm shooting either on vacation, or for a client, and enough storage that I don't have to dump my CF cards before I return home.
For example, I'll do a daily transfer to my laptop with the EOS Utility (it flags files already transferred), and if I have access to the internet, all those files are backed up by Carbonite to secure servers out in the the web cloud (very cheap, and very reliable). Just for an extra paranoid measure of security, I leave the files on my CF cards as well until I get home, and I am sure that everything is safe.
You don't have to do that, of course, but the more copies in the field, the better off you are. I don't know if my iPOD can store RAW data, but there are fairly cheap devices out there that are made for the purpose, if a laptop is out of the question. In that case, I would still suggest using large CF cards, and leaving the files on those cards until you get home.
I currently use 16 gig SanDisk Ext III cards, which can hold around 1400 RAW images each (on a 40D), and can accept data as fast as a 40D can write it (faster than the Ext II series, which is fine with a 30D, but is a cork with the 40D). Two should take care of a two week vacation with ease, but I keep three on hand just in case.
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Voyager