JRO:What about an IPod Photo? Could that capture RAW and display it (although it would a be a very small display)
I have not tried iPod photo but I don't think it is compatible with a lot of the RAW files.
I have an older iPod (2 years old) that I was going to use as photo storage on long trip but gave up the idea immediately because battery life is way too short. If you have 2x 4GB cards to download, the battery will most likely died before you complete the download unless it is plugged in. May be the newer iPod has better batteries capacity but you might want to check this out first.