Describing the exciting and adventurous world surrounding geocaching -- a world-wide hunt in which treasures are located using global positioning system (GPS) devices -- this manual offers an understanding and application of the principles and best practices of the sport as well as information on the different types of caches and competitions. With rich illustrations complementing secrets culled from experts, this resource gives participants with basic knowledge new skills for enhancing their experience and provides a visual montage of the different kinds of spots hobbyists can expect to find in the field. Additionally, the dozens of interviews from dedicated geocachers exhibit how the pursuit of hidden treasures has helped people heal frayed marriages and establish new friendships -- and even saved lives.