Since I just mentioned this in the Game area, I thought I'd write about it in the hobbies area! Anyway, letterboxing is really cool if you like being outdoors or like cracking codes and unravelling clues to find a treasure hidden away. Basically you go online and find clues for boxes hidden in your area [or an area you're visiting] and you solve the clues, and follow them to the place where the letterbox is hidden -- often in parks, areas with famous landmarks, cemetaries, etc. They're usually hidden inside tree holes, under rocks, below trees with leaves covering them, inside hollow logs or tree stumps.. It's limitless really. If you can fit your box in and hide it completely it's fair game to use as a hiding spot. Inside the letterbox you'll find a logbook and a rubber stamp with an image usually somehow related to the area you found the box in [eg, Lion Park might have a hand carved lion stamp]. You stamp the box's stamp into your own personal logbook, and then stamp your own personal rubber stamp into the box's logbook to show that you were there. Then you rehide the box exactly where you found it. Sometimes the clues are as easy as "find the statue and walk 20 paces North-east to the tree-line..." but sometimes they are really difficult and cryptic.

My favorite letterbox find so far was in an abandoned cemetary. The clues involved inscriptions on the few remaining grave's headstones, and also some more cryptic clues that I really had to spend some time looking around the cemetary and thinking about, in order to decipher.

I think there are somewhere around 300 letterboxes hidden here in Minnesota, with new boxes being hidden all the time. It'll keep me busy for a while!

If anyone's curious:
http://www.letterboxing.org/
http://www.atlasquest.com/

I'm not really an outdoor-sy person, but it sounds interesting.