One of my family's other hobbies is geocaching, which involves finding an item that's been placed in a location, with its GPS coordinates published on a geocaching web site. Often these items are containers, and people put things in the container so that the finders can trade items and have a memento of their find. A few years ago some of the cachers started a company that will make customized tokens about the size of a quarter that can be left in the caches and traded with other people online. We recently created a token that combines two of my hobbies, birds and insulators. If you see me at a show and ask nicely, I might give you one!