One of the hottest items around for cars, boats or even your pocket is a global positioning system (GPS). Originally developed by the U.S. Department of Defense, the system, officially named Navstar GPS, is based on a series of 24 satellites operated by the U.S. Air Force's 50th Space Wing. Before 1983, this was strictly for the military; civilians had no access to it. However, all that changed when the Soviet Union shot down commercial jet Korean Air Flight 007 after it went off course. Had the Korean Air pilots had access to GPS technology, the tragedy that killed 269 passengers could have been averted. After that event, President Ronald Reagan issued an executive order to make the system freely available for civilian use as a public good.

Today, GPS is one of the most widely used navigational aids in the world. The ground units (such as the one on a dashboard) access the satellite signals to determine their position, allowing them to tell you exactly where you are, along with your direction, speed and time. From there, data stored in their memory can then record where you have been and tell you how to get where you are going in terms you can easily understand.

Bonus: once you buy a traditional GPS unit, there are no setup or monthly fees.

Our Favorite Handheld GPS Unit

Garmin's eTrex Vista ($214.27)
The eTrex Vista is one of the best handhelds on the market for the price. The Vista comes with a full basemap of the Americas, the Atlantic or the Pacific Rim (depending on the version you choose), each loaded with detailed maps of lakes, rivers, cities, interstates, national and state highways, railroads and coastlines in addition to the unit's preloaded marine navigation aids. With 24 MB of memory, you can add on extras from Garmin's line of MapSource products. Along with these, the unit's built-in electronic compass and barometric altimeter allow you to pinpoint your precise position, while using the WAAS increases the Vista's accuracy to within three meters. garmin.com
Bottom line: Portable and affordable.

Our Overall Favorite GPS Unit

Garmin nüvi 750 ($535.70)
The nüvi 750 is a sleek, beautiful unit with a bright 4.3-inch screen that is readable from any direction. Ready to go right out of the box with preloaded City Navigator NT street maps that includes millions of points of interest, ranging from ATMs to service stations, 2-D and 3-D maps and turn-by-turn voice directions, the unit is designed for the user's peace of mind.
We're talking tools and entertainment here including an MP3 player, an audiobook player, a JPEG picture view and a currency converter. With its FM transmitter, you can hear your MP3s, audiobooks and directional voice prompts through your car stereo. The nüvi 750 also sports the Garmin Lock anti-theft feature, plug-in SD cards that provide language translation and travel guides, and a variety of ways you can customize your nüvi. garmin.com
Bottom line: A great multi-tasker.

Our Favorite Up-and-Coming GPS Unit

GETAC Handheld PS535E (Price TBD)
If you are anything like this reviewer, then you don't baby your technology. With the recent release of the PS535E from GETAC, you don't have to. Specializing in hardened technology fit for the shop floor, the great outdoors and the battlefield, this unit can deal with all the shocks and drops, spills, impacts and environmental hazards you can throw at it.
This unit comes with all the bells and whistles. It runs on Windows Mobile 5.0 Premium Edition, and offers a 3.5-inch LCD screen, a high-sensitivity GPS receiver, Bluetooth wireless local area network (WLAN) connectivity, an SD slot, 2 GB internal memory and a long-life battery for all-day power.
The hardware isn't the only attractive thing about this little handheld; the software includes the mobile versions of Microsoft Word, Excel, PowerPoint, Windows Media Player 10 and Internet Explorer. There is also an inbox, calendar, contacts, instant message, tasks, notes, spell checker, and Microsoft ActiveSync 4.5. getac.com.
Bottom line: The next generation of GPS.

Now Available:

Web-Connected GPS
It was only a matter of time before GPS and the Internet hooked up. The Dash Express ($399) offers state-of-the-art GPS navigation augmented by an Internet connection to provide what the company says is the most comprehensive traffic solution ever. Whether it is the ultimate solution to the problems of finding your way from place to place remains to be seen. What is for certain is that the Dash Express is a major step in that direction.
Why We Like It
Thanks to its innovative two-way Internet connection, the Dash Express is loaded with features including preloaded maps of all 50 states and the ability to define the route to your destination using the 2D map, 3-D map or a detailed turn-by-turn directions list. You can even generate maps of points of interest. On the Internet side, TrueTraffic, which gleans up-to-the-minute traffic information from the Dash Driver Network, comes standard. This system allows you to customize the information you would like to see, receive three routes for each destination as well as on-screen traffic alerts that give you the chance to change your route.
Functionality is further enhanced through the Yahoo! Local Search/Unlimited Points of Interest system, which offers preloaded points of interest (POI) as well as access to an unlimited number of POIs through Yahoo Local Search. For example, you can find filling stations and compare gas prices or find what movies are playing and then plan a route to the theater of your choice. What's more, you can do it through the Dash's on-screen keyboard. Other features include Send2Car, which allows you to send addresses to your device from any Internet-connected computer; and MyLists, which helps you to customize the search lists created and updated by you or other Dash users. Automatic updates, flexible WiFi settings, day and night modes, theft deterrence and useful third party content all round out the Dash Express picture.
Why We Don't
The only problem that we have is that the Dash Express is strictly for the car. It is not built for boats or planes, nor as a handheld GPS. For the price tag, we were hoping for more in this area. Beyond that, to receive the additional Internet-powered services, there is a monthly fee that ranges from $9.99/month for a two-year plan to $12.99/month for a month-to-month plan. Check it out for yourself at dash.net.