Letterboxing North America. You can also find out more there about how to join in and what to expect. Once you find a box, it will contain a hand-carved stamp, a log book, and possibly an ink pad. The finder stamps their personal logbook with the stamp they find, and leaves their own stamp in the logbook of the letterbox. If you're kind of confused like we were, but want to learn more...check out Letterboxing North America, and a post about a first-hand experience from blogger Baroque Babies.