A standing rule of the high-tech market is that as a thing gets smaller it gets more expensive, and if it gets very small it gets very expensive. That's the odd thing about the Fujitsu/Siemens Pocket Loox N100 Series GPS: It's smaller than just about any other GPS device, but it doesn't cost more. And in spite of its small size, it's got the features you'd expect from a GPS.

How small is it? The Pocket Loox N100 measures 3.5 by 2.4 by 0.6 inches, and weighs 3.9 ounces. Even though it's smaller than a 30-Gbyte iPod, it's got a bright screen that's 2.8 inches on the diagonal. That's just about as small as it can get and still be seen if you mount it on your car's dash and don't try to hold it in your hand (which you shouldn't do, because handheld GPS units, like handheld cell phones, make you a driving hazard).

Even at that size, it's got a good range of features. You can elect to see points of interest displayed from a large database of restaurants, gas stations, and so forth, or enter your own. You can use the device for ad hoc navigation (enter a destination and route to it from your present location), or you can save destinations or entire planned routes composed of multiple waypoints. You can even speak your destination, if it has a saved "voice command" attached, and the unit will route you to it.

Or if you'd just rather listen to MP3 files or play games, the N100 will do that, too. (There are some available features the evaluation unit didn't come with, like Bluetooth support so you can use the N100 and your cell phone together, or Traffic Message Channel alerts on road construction and tie-ups.)

Of course, ". . . doesn't cost more," doesn't mean that the N100 is free. It lists for $499, which is comfortably below the top of the range for larger devices with similar features, but you'll pay in other ways for the extreme cool of the good design and small size. There's not much room for a battery, for instance, and even though the specs rate the unit at five hours of battery life, that seems optimistic. If you're going to use it as an in-car navigator, of course, you can use the cigarette-lighter adapter. (The kit also includes AC and USB cables.)

Small Device, Small Interface
A bigger problem with the device's size is that it's so small there's not much room for a user interface. It has exactly two buttons -- on/off and hold -- and comes with a stubby stylus to use on the touch-screen. You work your way through menus to add destination information and set system parameters, like whether you want to avoid interstates or ferries, or block out a certain stretch of road. As with many small, stylus-driven devices, data entry isn't particularly easy and the menu-driven UI isn't particularly intuitive. If you want to know what the Pocket Loox is really capable of, you'll have to read the manual. And you'll want to keep it handy to go back to brush up on how to perform seldom-used activities such as changing the points of interest displayed while you navigate.

That said, however, the N100 delivers an out-of-box ease of use that will make it attractive to people who aren't computer nerds. Its maps are easy to read even on the small screen, and the 3-D versions are useful and attractive. Its turn-by-turn directions, both in text lists and in the unit's spoken directions, are clear and easy to follow. It does a good job of recovering from pilot error, too -- it shows you the start and end points you've chosen when you start navigation, just to help you avoid going to Salem, Oregon, when you meant to go to Salem, Mass. And when you miss a turn en route, the N100 quickly recalculates the route to get you back on track, and continues to reroute as long as necessary to get you where you want to go.

The manual provides good instructions for operating the N100, but lacks any information on how to change the maps on the Mini SD card, or how to update maps and points of interest. A DVD with European maps came with the N100 evaluation unit, and presumably you can expect to buy additional map files and updated data in the future.

The N100 is based on the SIRF Star III GPS engine, and runs on a customized version of Navigon's MobileNavigator Premium software that manages the maps, the touchscreen, and the multilingual user interface. The unit includes a Mini SD card for storing both map data and MP3 files (it accommodates cards up to 4 Gbytes), and comes with a kit that includes a car holder, car charger, AC adapter, USB cable, headphones, two face plates, and the all-important manual.

If you have ever lugged around a laptop in your car to use as the display for a GPS, or struggled to set up an older GPS device, you'll appreciate the pocketability and ease of use of the N100. And if you've ever thought a pocket GPS looked like it might be fun, you're right. But that doesn't mean the N100 is just a toy. It's a very good navigation tool in a very small package.