Just before we took off, our friends got equally excited with our plans and started giving us challenges to do. The straight forward ones were to visit the compass points of the mainland, swim in the coldest water (Lake St.Clair), climb the highest mountain, etc. Then the kids started getting more from their friends, things like catch a fish in every state, spotting different animals (e.g. Tassie Devils), learning to tie different knots, sending pictures of patting a safe native animal, and the list went on.
It gave them something to focus on, kept them in touch with their school friends back home, and made them think about where they were at any time, adding to their education, as well as ticking off the lists.
What does everyone else out there do to keep the kids occupied and interested as you move around?