With so many GPS receivers entering the market, it may be difficult to know which one to choose. Originally designed by the United States Department of Defense, GPS has become a part of the mainstream, used by drivers, hikers, golfers and urbanites alike.

Global positioning systems use various satellites, which send microwave signals to the earth, in order to determine the location, time and velocity of the waves. With size and cost constraints, no GPS receiver does it all. However, many GPS users feel that what they can do is pretty cool.

You will have to decide which one you want, depending on your needs, since once you a buy a GPS receiver, you're also buying into its capabilities.

1. The most basic gps receivers for sale provide navigation capabilities as well as time and location without mapping capabilities.

2. Some GPS receivers have been designed to weather the elements. Others have no waterproofing capabilities.

3. Consider how large a screen you will need. When driving, for example, you will probably want a much larger screen than if you are on a long bike ride.

Action Steps
The best contacts and resources to help you get it done

Buy a handheld GPS receiver for hiking, geocaching and getting around

Almost anyone can use a handheld GPS receiver, although their functions vary depending on their design. A handheld GPS receiver is a convenient choice for hikers, bicyclists, golfers, fishermen and urbanites. Since functions vary, check reviews to the find the one that best suits your needs, including whether you want mapping capabilities.

I recommend: Best Buy sells several handheld GPS receivers as does REI. Both include honest customer reviews on their websites. ExtremeGB Ltd carries many handheld GPS receivers, all with thorough descriptions and outlines of their uses.

Buy a wireless GPS receiver for urban environments

Wireless GPS receivers work with pocket PCs, palm devices and smart mobile phones and are usually designed for more urban areas.

I recommend: Negri Electronics carries a variety of GPS receivers as well as a couple of wireless GPS receiver models. PC Universe, Inc. also sells many GPS receivers, including those with wireless GPS technology.

Purchase GPS video receivers for trucks and automobiles

If using GPS in a vehicle, most drivers prefer GPS video receivers, which contain a screen large enough to see while driving.

I recommend: TheNerds.net sell many GPS receivers, including those designed for vehicle use. Costco Wholesale Corporation has several GPS video receivers for sale on its website, all created for navigation assistance while driving.

Buy USB GPS receivers for your lap top

USB GPS receivers take an ordinary laptop and transform it into a GPS navigation system.

I recommend: Office Depot, Inc. sells USB GPS receivers. Buy.com Inc. also carries USB GPS receivers.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  If you need accompanying software for your location, be sure to buy that as well. If you're out in the woods, even popular trails will not be shown on all portable GPS receivers.