Today, most GPS units come with real-time mapping software that provide users with a map providing the best and shortest route from one point to another. A new breed of such units has appeared on the market which also provide other alerts apart from the shortest route information. For example, suppose you were traveling from one location to another following the generated map on your GPS unit and suddenly there is a road block in your path. A GPS unit with traffic alerts, like the TomTom 930T, will be fed this information from a centralized traffic server and will show you the exact location where the blockage has taken place along with the best alternative route or routes. This is no doubt a great inconvenience for the busy executive going to attend a meeting or to the doctor who needs to reach the hospital immediately to attend a life saving operation. This feature built into certain GPS units ensures that the busy executive will reach his meeting in time despite the jam on the highway; and will also ensure that the doctor reaches the hospital faster, since the GPS unit has provided him with details of an alternate route that is less congested. As you can see, there are many benefits of a GPS unit with built-in traffic alerts.

If you're in the market for an advance GPS receiver, TomTom GPS Deals offers many GPS units with traffic alerts. Also, you can buy a GPS traffic receiver accessory separate from the unit.

Garmin

Garmin  currently manufactures 26 different models of automotive GPSs that range from the most basic with a square screen to very advanced with extra-wide screens.  They come pre-loaded with maps with most are able to speak the names of the streets. More advanced models come equipped with Bluetooth wireless, are voice activated with lane assist, have a route planner and have an FM transmitter and MP3 player. Besides automotive GPSs, Garmin also produces more rugged GPSs for motorcycles,  hand-held models for hiking, models made specifically for golfers, runners or cyclists as well as those made for boats and airplanes.

TomTom

Unlike Garmin, TomTom only manufactures GPSs for vehicles and motorcycles. They do, however, have special programs and features for business owners and those who have fleet vehicles. TomTom currently has models ranging from the basic ONE models like the TomTom ONE XL/S to the advanced PRO series. All models come with the innovative Map Share technology which allows users to update their own road maps in real-time if they come across a road that has been diverted or a newly constructed road. They also can receive updates made by others to keep the maps as up-to-date as possible.

Magellan

Magellan is well known for its Triton hand-held GPS models, but they also produce automotive models. The Maestro model comes with a few more bells and whistles such as AAA Tour Book and Bluetooth as well as the ablilty for live traffic updates. The RoadMate is a little more basic, but both models have up to 6 million points of interest as well as the ability to speak the road names.

If you're in the market for a GPS device, you can't go wrong with these top rated portable GPS brands.

Until a few years ago, these tasks would have been considered impossible, but today even sailors navigating the high seas to travel from one country to another rely on these portable GPS units. The portable GPS (global positioning system) unit or receiver can identify your exact location through the help of 21 active orbiting satellites that are stationed at a geo stationary location, 12,000 miles above the surface of the earth. This satellite system has been designed in such a way that they can track your movement and send details about your location to your GPS unit irrespective of your location on earth.

You might be high in the mountains or deep in the jungles or even crossing a great desert, yet these units will report back your exact location with unfailing accuracy. At any given point of time, 3 of these 21 satellites send signals to your GPS unit and the signal sent back to the satellite by this unit helps the software on the satellite to pinpoint your location by using a grid that tracks your location in latitude and longitude.

If you need a portable GPS unit, check out the bargains at TomTom GPS Deals.