The first step to choosing a unit is looking at all of the different categories that are available. The six basic categories of units are automotive, handheld, PDA, laptop, aviation and marine. The most important thing you need to do is decide which one you need based on where and when you are going to use it.

Basic handheld GPS units are generally less expensive and can even be as low as one hundred dollars. They are just as accurate as the more expensive handheld units, but they do not have as many specialized features. Most basic handheld GPS units have or can display your location, usually in the format of your choice, a compass heading, the elevation above sea level, the accurate time, typically in both twelve and twenty four hour formats, satellite location and signal strength, the ability to calculate the distance traveled, the ability to record your path as a set of waypoints, the ability to navigate routes, and the ability to retrace your steps. The main thing you will find in the most advanced handheld GPS units that you will not find with a basic one is the mapping capabilities.

Handheld units are great because they can vary so much in size, which makes them very easy to customize them for whatever your needs may be. Some of the smallest ones are as tiny as a basic cell phone and this can make them very easy to travel with you, whether you are walking around a new town or camping on a backpacking trip. Also, handheld GPS units are completely self contained, which means that there are no external attachments. However there are some exceptions like the ones that have receivers that run on external power, like from a car. Also, some units have are built with a jack for an optional external antennae and other units can be connected to a laptop or a PDA for expanded uses.

There is another group of units known as handheld mapping GPS receivers. These units display maps that are pre loaded onto the device, but have been uploaded from a PC. These units are typically larger than the ones that do not have mapping capabilities, but they are still fairly inexpensive. Regardless of which one of the handheld GPS units you choose, you will be happy that you got one, especially the first time you find yourself lost in the woods.