Emerging Technology

Somewhere in the hills of Merom Bluff Park in Indiana, up above the Wabash River, sits an ammo box filled with bric-a-brac: old Frisbees, rubber money, toy dinosaurs, key chains. Odds are that in the next few weeks, someone armed with an advanced Global Positioning System (GPS) device will attempt to find this box. Not because it holds anything of value. In fact, the explorer who tracks it down will end up swapping a few items and leaving the box where it is. Such are the rules of the curious new pursuit known as geo-caching: Someone puts a few trinkets in a box somewhere and uses the Web to publish the GPS coordinates (latitude and longitude) that tell where the cache is. Intrepid geo-cachers will then use their tracking devices to find the box, dutifully remove a few items, and contribute a few new ones of their own.