I've traveled with my iPhone a lot (basically the same as an iTouch when you don't have cell coverage). It worked great as a way to communicate. When I was in China and Peru, I was able to send e-mail and more importantly... Skype (.02$ a min from China and Peru to a US land line). On top of that, it's compact, travels very well, and can go for a really long time on batteries.
USCG Master 100T
S/V Priorities (79' CAL 31)