Thanks! Yeah, I wish I could to something like that for everyone who's done something nice for me... sadly my gratitude sometimes exceeds my creativity.
When we tour in places other than Australia, Rowan buys up a collection of Australian pins (little kangaroos etc.) and passes them out to anyone who has been particularly helpful ... even with directions to a campground or something when we're completely lost.
It's not anything big, and they are not heavy or bulky to carry around, but it's one way to say "Thank you" with a bit more impact than just saying the words.
I've also done things like sending nice Canadian calendars to people I've stayed with, with beautiful scenes from across Canada.