Geocaching Swag Shadow Box - fun idea (not mine). I'm going to stop overlooking the contents of the larger caches and start swapping for the most unique trinkets. Collecting them may add another dimension to the fun.
This is such a fun idea! or use dremel tool on a real brick. Perhaps a small real Lock & Lock could be used instead of a film canister. Would be watertight and more fun to be able to leave signature items and travelbugs.