Letterboxing is an intriguing pastime combining navigational skills and rubber stamp artistry for a treasure hunt style outdoor quest. Enthusiasts use clues to track down hidden letterboxes, then record their successes in logbooks. Site explains the origins of letterboxing, gives instructions for beginners, and provides clues to letterbox locations in each US state and Canadian province. Similar to geocaching, but without the use of GPS tools. - [Read more]