Millions of road warriors have finally traded the folded gas station map in the glove compartment for a handy global positioning system (GPS) unit.
You know, those small doohickeys that communicate with satellites hovering above the Earth to pinpoint your location on the planet. With built-in maps for the entire U.S. (and usually, most of North America), GPS navigation units can help you reach to your destination with turn-by-turn visual and audio instructions.
