I had no idea such a thing existed. Basically, geocaching is high tech orienteering. Using the lat/long coordinates of a particular site, you use your hand-held GPS unit to navigate to the "cache". The cache usually is a waterproof container filled with strange trinkets and a log book. Etiquette requires that you "take something, leave something, sign the book". It's hard to imagine that such a thing would actually work in this day and age, but apparently it's flourishing. now purports to know about caches in 174 countries. I was surprised at the number of locations just within central Arkansas. In addition the caches, dropping a travel bug is now common practice. A travel bug is a barcoded set of dog tags that lets people track the movement of items from geocache to geocache. Some of these items have been around the world several times through thousands of hands! So, need some exercise and a little outdoor activity? Log on, look up some coords, grab your GPS (now as cheap as $90) and head for a new cache.