GPSMonitor displays your location on a map by feeding your latitude and longitude to this page. This map will appear if you have your USB GPS or serial GPS connected to your computer, and have an active web connection.
The map is also able to show convenient neighborhood shopping locations if you're not hiking in the back country using a satellite phone for your internet link. Who would want to carry a laptop hiking in the deep woods, anyway?
If this map shows you off in a blank wasteland, please email some of your raw NMEA data to me so I can see why it's doing that on some GPS systems.