GPS Visualizer (GeoVisualizer) is a free utility that creates customizable maps and profiles from GPS data (tracklogs & waypoints), addresses, or coordinates.
GPSBabel converts waypoints, tracks, and routes between popular GPS receivers and mapping programs. It also has powerful manipulation tools for such data.
GPS TrackMaker is a communication program to connect GPS to PC. It allows the creation and edition of Waypoints, Tracklogs and Routes. It still allows to insert a scanned image of map.
Geocaching is a treasure hunting game where you use a GPS to hide and seek containers with other participants in the activity. Geocaching.com is the listing service for geocaches around the world.