When GPS devices first came out, I was characteristically ho-hum about them. An early adopter of tech gadgets I’m not.Well, I’m here to say that people a lot smarter and more adventurous than I have dreamed up a clever use for these units. Think of a scavenger hunt, throw in the connectivity/community of the Internet, add a GPS receiver (or a GPS-enabled mobile phone containing Geocache Navigator software, which costs around $7 per month) and you’re on your way to understanding the increasingly popular activity known as geocaching. Briefly, the term combines the words “geography” and “caching,” which, according to Geocaching.com, “is the process of hiding a cache.” The one who hides the cache is the “owner” and those who set out to find it are the players. The fun begins when the owner selects a location for his or her cache that is a challenge to reach, even with a GPS receiver. Some caches require the players to be scuba divers or rock climbers, and some are concealed on well traveled city streets. To give it a try, you’ll need a GPS unit. The site recommends the Garmin eTrex GPS ($90) or the Magellan GPS 315, We couldn’t find that model so we recommend the new Magellan Triton 300 instead ($150); it lets you add detailed maps and applications. In addition to the thrill of the hunt, players may find themselves rewarded with items left in the cache. Or maybe not. The only thing a cache has to contain is a logbook, but that doesn’t mean it won’t contain jewelry, money, tickets, or other valuables. Players must be prepared to leave something in the cache if and when they take something from it. Read the FAQ page for more about this fascinating new form of recreation.