Describing the exciting and adventurous world surrounding geocaching—a worldwide hunt in which treasures are located using global positioning system (GPS) devices—this book offers an understanding and application of the principles and best practices of the game. What's different is that the authors wrap this knowledge in a tapestry of human stories that range from hilarious to touching. Paul and Dana Gillin interviewed 40 of the world's 50 most prolific geocachers as well as experts in container design, "extreme" geocaching and other dimensions of the game. They tell how this global activity inspires passion that has helped people heal frayed marriages, establish new friendships—and even save lives.