Great GPS Gadgets


location based services

If you don't know where you are and you don't know where you're going, then you are, as they say, lost.

When thrust into the unknown without navigational aid, travelers quickly fall into a state of informational paralysis, the consequences of which can range from simple embarrassment to starvation and death. The need to locate oneself has been the motivating force behind thousands of years of technological innovations: the astrolabe, the sextant, the compass and years of refinement in the science of mapmaking.

But when it comes to finding oneself, none of the developments of the past come close to the near-perfect accuracy of today's Global Positioning System.

The U.S. Department of Defense developed the system as an aid for military navigation and targeting, and in 1974 it began deploying a constellation of 24 Navstar GPS satellites around the globe; the system became fully operational when the last satellite went into orbit in 1993.

View a slide show of ten great new GPS devices.
Civilian GPS equipment emerged in the late 1980s, but the Pentagon built in electronic errors to limit the accuracy of non-military devices to within 300 feet. In 2000, President Bill Clinton ordered the intentional errors--known as selective availability--turned off, increasing the accuracy of civilian devices to between 30 and 60 feet.

This ushered in the golden age of GPS, spurring the development of numerous handheld and automotive navigational systems. Trust in satellite-based navigation has become so absolute that British motorists have been known to drive down closed roads right into rivers--simply because their nav systems instructed them to.

In the past few years, electronics manufacturers have noticed that GPS technology is useful for purposes beyond basic navigation, and they have been creating new gadgets accordingly.

When integrated into cellular handsets, GPS receivers can alert users when they are near a location of interest, help 911 operators locate callers in distress, or allow worried parents to track their children's movements.

Advanced automotive GPS navigation systems now incorporate real-time traffic data from satellite radio services such as XM (nasdaq: XMSR - news - people ) or from terrestrial radio broadcasters. These devices can automatically reroute you when accidents or congestion block the road ahead.

And some cameras use GPS to add "geotags" to digital photos that identify them by the location where they were shot.

As the uses for GPS have evolved, so has the satellite technology that enables it. The U.S. Air Force, which runs GPS, is busy developing a new generation of Navstar satellites called GPS Block III. The new constellation will be jam-proof for military users and more accurate and powerful for civilians. Meanwhile, Europe, eager for its own system, is busy building a constellation of satellites called Galileo.

As the price of GPS receivers comes down, the number of uses for the technology will only go up. In many industries, GPS chips are already used to track trucks and cargo shipments, but when the technology approaches the disposable level, don't be surprised to find GPS in everything from dog collars to luggage to FedEx (nyse: FDX - news - people ) packages.

After all, the more you care about something, the more you want to know where it is.

View a slide show of ten great new GPS devices.