Have you stored RAW files on an iPod?
TBH: no. Because it was 3 to 5 years ago (I used a third generation iPod) and I didn't yet shoot RAW (not many people yet did, then). So I don't really know if iPods will store RAWs.
But that was when photo memory cards were still screamingly expensive. With todays prices (and card sizes) I can afford to have 36 Gigs with me. More than enough for 3 weeks in the Amazon, or Antarctica. And flash solid state memory is far and away a much, much more reliable and safer storage method than mechanical spinning harddisks (like the iPod has got) are.
So no portable photo storage devices for me anymore these days. Solid State memory all the way.
And should you take your laptop on a trip, then you can also burn your photos onto DVDs (and send them home using snail mail?). OR – if you have access to broadband en-route – you can send your photos home, to your own email address, through Podmailing.com (FREE, unlimited file size). Very safe! So even if your gear is lost, stolen, or impounded by shifty authorities, your irreplaceable photos will be waiting for you at home!
(And you can empty and re-use your cards again. And again. And again).