GPS systems have become invaluable in recent years, helping people across the globe find their way through cities, towns, countryside, mountains, and through middle of nowhere for years. GPS systems are utilized as hand held devices, can be found as a feature on cell phones, and can be mounted in cars. These systems, known as Global Positioning Systems, use satellite signals to define locations and destinations in the map databases of these devices. Each satellite completes one orbit around the Earth every 12 hours, and they carry an atomic clock, transmitting a position signal and a time signal that is picked up by the GPS receiver. This allows the unit to perform all kinds of necessary calculations to arrive at a fixed location, usually accurate to within about 50 feet.

There are two main types of GPS receivers for consumers, the handheld kind and the kind for autos. Although the two kinds serve the same purpose, they are very different in most ways. First, handheld units that many people use outdoors while hiking, biking, and the like, are made to resist the elements wind, rain, ice, humidity, etc. They are usually made of water resistant material or rubber to absorb shock if it is dropped. They are smaller than auto GPS units and should be comfortable to hold with one hand. The display screens on the handheld units are smaller than vehicle units, and a common issue for the handheld gizmos is that they require substantial battery life to operate.

Auto GPS units are commonly larger than the handheld ones. They are portable also, but do not cooperate well when out for a hike. They are not waterproof or water resistant, and the larger screens make them quirky and heavy. The big screen also sucks the life out of the battery quickly, but fortunately almost all models can plug right in to the cigarette lighter adapter. Many of them talk to the user, giving audio directions and using highway and road maps. Handheld units only come with basic maps, if they come with a map system at all. So, if you are trying to decide whether to get a handheld unit or an Auto GPS system, weigh the pros and cons of each, then as a final judgment call, figure out if you need directions more often when you hike and bike or if you get lost while driving more.

There are many companies that manufacture GPS systems for cars. Some of them are made by companies such as Garmen, Jensen, and Magellan. From big time household brand names to the less well known guys, GPS makers continue to add features and gadgets to the systems that make consumers ooh and aah at the technology, even while driving.