It is more than difficult to find a good GPS review on the Internet. The reason is this: GPS devices all do the same thing. They show your location on an electronic map, and then show you how to get where you're going. Now, by GPS device I mean a car GPS device that you buy separately from your automobile and either hang from a bracket on your windshield or put next to you on the seat.

So, the key to a good GPS review is understanding the features that various GPS devices offer at each price point.

What do all GPS devices have in common?

All car GPS devices that are on the market today have a touch screen where you can enter information into the unit, such as your destination address. All auto-calculate the route to that address, and all give you spoken directions of some sort as you drive to your destination. In addition to this, virtually all GPS devices come pre-loaded with maps, usually at least of the continental United States, have an internal battery for emergency use, and can toggle between 2D and 3D map views. (3D gives you a slightly more realistic view of what you should be seeing in front of you.)

There are exceptions to all of these rules, but almost all are in the older models.

Who are the industry leaders?

There are three main manufacturers of car GPS systems, Garmin, Magellan, and Tom Tom.

Garmin sells about one out of two of all the car GPS systems sold in the world. They are known for making a quality product. Magellan was an early leader in GPS systems that can route you to more than one destination. They do not have nearly the market share that Garmin has. Tom Tom is a late arrival who is quickly catching up. According to Tom Tom, their GPS system, the Tom Tom One, is the best selling system in the world.

What are the main features to look for in a GPS system?

In this GPS review, let's start at the cheap end and work our way up.

You can buy a GPS system for less than $200. The Garmin nuvi 200 and the Tom Tom One, 3rd Edition currently sell for less than $200 at Amazon.

As you increase price, the main features you can add are

Voice prompts that actually say the street name

Cheaper GPS devices only tell you where to turn. They say something like, "Turn right, here." A good feature to be aware of is having the GPS device actually say the street name of the road you need to turn on. So, instead of "Turn right, here," a better GPS system would say, "Turn right on Highland Avenue," or "Take a left onto the entrance to I-95." Devices with spoken street names usually start around $300.

Another feature to look out for is real-time traffic and weather capability

Wouldn't it be nice if your GPS device could not only tell you how to drive from Atlanta, Georgia to Charlotte, North Carolina, but could alert you to bad traffic conditions in time to take a detour? Well, many of the more expensive units can. How does your GPS device know what the traffic is like up ahead? GPS devices that have this capability are tuned to either an FM or satellite radio frequency that broadcasts this information. If your device has this function, then it will usually come with a free trial subscription to this service. After that, it's going to cost you, but the cost is fairly low, especially considering how useful real-time traffic is. Along with real-time traffic usually comes real-time weather -- an added bonus.

Any of the Garmin nuvis from the nuvi 350 up have FM traffic capability. The nuvi 350 runs slightly less than $300 at Amazon. If you want a Magellan that route you around hold ups, you'll be paying $300 to $350. All of the Tom Tom's have this capability, even the Tom Tom One, 3rd Edition, which is one of the cheapest units on the market, currently running around $200.

Do you regularly use your cell phone while driving?

I know I do. It's problematic to hold the cell phone in one hand and negotiate your way through heavy traffic on a busy interchange. If your phone supports Bluetooth technology you can get a GPS receiver with that same capability and actually use it to make and receive calls. You answer an incoming call by just tapping on the touch screen. You make an outgoing call by either entering the number in your GPS's touch screen key pad or by accessing numbers stored in the device -- downloaded from your phone when you first set up your receiver. So, now instead of wearing that silly Bluetooth headset and looking like a member of the Borg Collective, you can just have your GPS device do double duty. If you make a lot of calls while driving, this is definitely a feature you need to think about.

As to what Bluetooth is going to run you, the Garmin nuvi 360 is their lowest priced Bluetooth model. It currently sells for slightly more than $300. Virtually all of their upper end products have Bluetooth. Two of the Magellan Maestro series, the 3250 and the widescreen version, the 4250 have Bluetooth. They run around $280 and $350 respectively. The Tom Tom GO series has Bluetooth. They run anywhere from $350 to $900.

Multi-destination routing

It's not something that I use much, but it's definitely worth knowing about. Multi-destination routing means you can enter multiple routes into your GPS at one time and it will calculate the best route that includes all of your destinations.

Garmin's nuvi 700 series does this, as well as a couple of their StreetPilot series. Most of the Magellan Maestro series does this - they can be programmed to hold up to 20 separate destinations. As for Tom Tom, the GO 510 can hold up to 15 routes. As to price, the nuvi 700s run anywhere from mid-$400s to almost $700. The Magellans are slightly less expensive, running from mid-$200s to the mid-$300s. The GO 510 costs slightly less than $500 at Amazon right now. The voice prompts, Bluetooth, and multi-destination routing are three of the more important features to consider.

Also, you want to keep in mind what maps your device comes with. And, almost as important, how many preprogrammed Points of Interest are included in its database.

Points of Interest

(POIs) are names, addresses, and phone numbers of possible destinations, anything from the nearest Starbucks to Yellowstone National Park. The lower priced units come with less than 1 million POIs. That's not enough, if you're going to be using this feature. For use outside of your normal travel routes, you really want a few million POIs. Virtually all GPS devices now come with this, except the lowest prices models, like the Garmin nuvi 200, which only has regional maps and less than 1 million POIs. (There's nothing wrong with fewer POIs, if you're not planning on needing them, but they sure can come in handy.)

Yet another feature to keep in mind is screen size. The standard size is 3.5 inches. This is measured on a diagonal. So the screen for the nuvi 270, for instance, measures 2.8" by 2.1". The so called widescreens measure 4.3 inches on the diagonal. You're actually getting 70% more screen this way.

Why is screen size important?

It has to do with ease and safety of use while driving. Personally, I like a wide screen, but then again, my car is fairly big and has a big windshield. The difference in price between a regular screen and a widescreen is about $80. That might be money well spent. On the other hand, if you drive a smaller vehicle with less windshield area, the wider screen might be more of a hazard than a safety feature.

Currently at Amazon, Garmin nuvis (their newer product line) run from $179 for the nuvi 200 to $699 for the nuvi 770. The Magellan Maestros are running from $168 for the 3100 to $356 for the widescreen 4250. Tom Tom's GPS systems are currently priced from slightly less than $200 for the Tom Tom One, 3rd Edition, to $899 for the GO 700 (which is overpriced).

Whatever you do, don't procrastinate. Even with a good GPS review, with all of these confusing choices it's tempting to just wait for whatever the next model is going to be. What you're missing by doing that is lots less stress while driving! Imagine, if you're a guy being able to always (really) know where you're going despite what your wife or girlfriend says. And, even better, if you're a woman you won't have to pester your husband or boyfriend to stop at the local gas station and admit that they're lost - not an easy admission for a guy. (I should know!)