Hidden treasure isn't just for pirates. Instead of a secret map on which x marks the spot, participants in the high-tech game of geocaching (pronounced "geo-cashing") use the Internet and GPS devices to track down more than 350,000 caches, or prizes, around the world. If your kids are into computers and electronics--and whose aren't these days?--geocaching can be a fun diversion, or even the highlight, on a road trip.
To get started, you need a GPS receiver that accepts waypoints--longitude and latitude coordinates, like N 44.46018 W 110.82779 (Old Faithful geyser in Yellowstone National Park). Units suited for hiking always meet these requirements, while some GPS devices intended for cars only use street addresses and won't work for geocaching. A basic hiking device costs about $100, and some state parks, outdoors stores, and resorts rent them.
Go to geocaching.com to find caches in the area you'll be visiting. You can search by state, town, area code, keyword, or coordinates. Because GPS devices are accurate only to within 30 feet, many listings--which are created by geocaching enthusiasts and never involve fees--have hints or riddles to help you home in on the prize. (But sometimes the hints are meant to trick!) "Look ahead to the 'V' in the tree," says one hint in Omaha, Neb., "then look for a 'house' close by." It's a reference to a birdhouse.
Before taking to the road, scout the area using Google Earth or live.com. "If the cache is on a cliff, it might require rock climbing from one direction, but from another you might be able to drive almost up to it," says Dave Ulmer, who invented geocaching in 2000. "You can be within 30 feet of a cache, but you're next to a pile of rocks, so you have to figure out which rock to turn over. That's when you need to think about the hints."
Caches are typically waterproof containers with a logbook and some sort of booty, which could be a CD, a book of poetry, trinket jewelry, or unusual coins. The Kiddie Cache in Omaha, Neb., usually has an assortment of Matchbox cars, dolls, hair clips, toy frogs, dinosaurs, and pencils. The rules say that you're entitled to a prize so long as you leave something for the next treasure hunter.