GPS makes navigation of all sorts easier. When you have a GPS device and an unobstructed view of the sky, you will never be lost again. There are a variety of GPS devices out there, and buying the appropriate one that fits your needs will help ensure that you get the most from your GPS device. After all, a device that does not work well for your requirements tends to sit on the shelf and not be used. This guide will help you ascertain the right type of GPS for your needs so that you'll get years of utilization from your GPS.

Step 1: Picking the correct type of device

Before you purchase a GPS, you need to understand the various types of GPS devices that are available and how each can meet your requirements. The major types of GPS units are: vehicle, handheld, and PDA attachments. The type of GPS device you select will vary based on your requirements, and the features you should look for will vary based on the type of unit you are purchasing.

Vehicle GPS units are a huge time save if you drive for a living or make trips to lots of different areas with which you are not familiar. Vehicle GPS devices usually come with features that make operating them in a car much easier: features such as automatic route finding which tell you where and when to make turns so that you can keep your eyes on the road where they belong. Some vehicle GPS systems feature technology that alerts them to real-time traffic-reports and they can re-map your route based on the existing traffic. If you plan on using your GPS primarily in your car, you should look at a device designed specifically for this sort of usage since these units tend to have bigger, easier-to-read, screens than most handheld units.

Handheld GPS devices tend to be the most versatile type of GPS units available. They can be used when walking, camping, driving, really any place you can go. However, this increased versatility normally results in a device that has fewer advanced features. Since the unit needs to be portable, the screen size is commonly limited and this can make many features of a GPS (such as breadcrumbs, route marking, visuals, etc) harder to use than a system that is fixed in a vehicle or that makes use of a larger screen on a computer or PDA. If you plan on using your GPS primarily in your car, a smaller screen may make it harder to use. If you plan on using your GPS when fishing, walking, or camping, this is most likely the best type of GPS for you.

GPS systems that plug in directly to a laptop or PDA often rely on the computer or PDA for all of the GPS functionality except for the gathering of the positioning data from the GPS satellites. Because a significant amount of the functionality is transferred to the PDA or laptop, the GPS system itself is usually much cheaper than a free-standing GPS system. But if you intend to use your GPS for camping, in marine conditions, backpacking, or hiking, bringing your PDA or laptop may make using your GPS unit more trouble than it's worth. As such, GPS devices that connect to another device are usually employed in cars and for people who navigate by foot in cities. If you are looking for the cheapest type of GPS unit available and you already already have a GPS-compatible PDA or computer, this may be the right option for you.

Step 2: Selecting GPS Features

Depending on the sort of GPS system your are getting, here are some features that you should consider.

Accuracy -- As a general rule, GPS units are accurate to within 50 feet. If accuracy is important to you , consider a unit with WAAS (wide area augmentation system) as this at least doubles the accuracy of your GPS device. This tends to be most useful in handheld units.

Address Finding -- Some GPS devices let you to enter a target street address. This can be very handy when driving and is a feature most often found in vehicle GPS devices or systems used in vehicles.

Automatic Route Finding -- This is often used in conjunction with address finding. This feature sets up the GPS so that it will tell you exactly where to turn to get to a pre-programmed address. This is a very useful feature for vehicle units, or devices used in vehicles, since it allows you to use the system without having to take your eyes off the road.

Built-in Maps -- Lots of GPS units come with maps that are built-in; for example, all of the United States. If plan to purchasing a device with a pre-installed map, make sure you get a GPS for your area, particularly if you are purchasing on-line. Also, make sure that the map can be updated.

Compass -- Believe it or not, there are GPS devices that do not include a compass except for when you are moving above some minimum speed (usually faster than a hiking speed). But there are also GPS units that come with true compass functionality even when you are not moving. This feature is usually most useful in handheld GPS devices.

Computer Compatibility -- If you are considering a GPS device that gets updated maps via a computer (which is most of them), and you are using a non-Windows computer (like a Linux machine or a Mac) be sure that the GPS system is compatible with the type of computer you have. Every GPS device that connects to a computer will support a Windows machine. But compatibility with other operating system varies.

Downloadable Maps -- Most GPS units allow maps to be downloaded into them. This is very nice for people who travel far-and-wide. It also makes it easier to purchase a GPS that has less memory since you can easily swap out the map to fit the area you will be in.

Expandable Memory -- If you plan to use your GPS device with maps, you will want to make sure that you have enough memory to support the number of maps you will be using. As it is with computers, the same is true with GPS devices: the more memory the better.

Extended Battery Life -- If you are going to be getting a handheld or PDA attached GPS system, pay particular attention to the battery life as this can often be the limiting factor in using your GPS.

External Antennas -- Some GPS units provide for an external antenna to be attached. This is very useful in vehicle devices where the satellite signal may be impeded by the system being in a car. It can also be helpful in portable devices as it allows you to keep the unit packed but still be operational for things like breadcrumbs.

Traffic Alerts -- Some GPS systems come with the ability to download real-time traffic information. If you drive in an urban area, this can be an incredibly useful feature even if you know the area you are in. This feature is most often available in vehicle units and in computer/PDA attached systems.

Water-Resistant/Proof -- If you are buying a handheld GPS unit and you intend to go hiking, camping, fishing, boating, or doing anything outdoors with your GPS system, think about looking for a unit that has some level of resistance to water. Also, be aware of the difference between waterproof and water-resistant. Water-resistant indicates that the system can be exposed to small amounts of water but it can't be completely submerged. If there is a probability your GPS will be completely submerged, you should consider a waterproof GPS, not a water-resistant one.