There are more than 700,000 active geocaches around the world, and now 78 of them are in Maryland. Geocaches are hidden containers, and geocaching is a relatively new outdoor sport in which adventure-seekers equipped with Global Positioning System devices hunt for those containers in parks and other public spots. The Maryland Municipal League is using this rapidly growing sport to promote awareness of and visits to it's cities and towns, with the goal of helping to stimulate economic development in these municipalities by introducing geocachers to places they would not normally visit. It became the first state municipal league to launch a statewide Geocache Trail, which is comprised of 78 caches hidden in cities and towns across the state. To play, participants need only download a list of each cache's latitude and longitude coordinates from Maryland's geocaching Web site. Once they've found a cache, they record their visit in the guestbook. The first 500 treasure-seekers who locate at least 22 caches will receive a "geo coin," which is a coin that is marked with a serial number that geocachers can register on the geocaching Web site before leaving it in a cache. They can then chart the coin's journey, and possibly even reclaim it one day.