John Grove - GPS & SatNav

	After much research, I decided that TomTom is easily the best navigation package for the price. Running on a Palm T3 - with it's 50% bigger viewing area - it's fantastic value. The biggest plus points for TomTom are the easy interface and the speed at which it operates. One of the reasons for TomTom's speed, is the fact that the whole of the map is loaded into the RAM memory of the Palm. With other navigation systems, time is lost while accessing data on DVD or some other Flash memory. It's not much fun sitting at a roundabout while you wait for the navigation software to catch up, I can tell you!! TomTom is a truly fluid navigation system. Even if you miss an instruction - or choose to ignore an instruction - TomTom will recalculate a route within a staggering six seconds.
With the supplied kit, TomTom mounts on the dashboard or window of your car as in the picture to the right. Routes can be calculated even before you get into your car, and pulled up out of the software by clicking "last destination". Alternative routes; routes avoiding; and routes to railway stations, and other points of interest are easy to find. You can create your own points of interest, and even import others from the internet. Destinations can be searched by post code, city or as points of interest.
	There's two different modes for navigation while you're on the move. In 3D view (left) some find it easier with the relatively uncluttered screen - but the downside is there's less information for avoiding traffic and you can't see as far ahead.
With the 2D view (right), there's much more information in view. In the image (right), you can see the zoomed in map when you're about to make a turn. TomTom automatically zooms in, then after the turn it zooms out again. In 2D I personally find it easier to avoid traffic jams, as you can see more clearly the layout of adjoining roads. Also - unlike in this example, I run my Palm in landscape mode so that I can see more detail left and right on my current position. Recently I bought the Western Europe map update, which now enables me to navigate across most of Europe, and in my own language!
	I bought my TomTom and Palm T3 package from Global Positioning Systems. I found them to be very competitive in price, and extremely helpful with their technical help - I'd thoroughly recommend them!
See the review of forthcoming TomTom Navigator 5
GPS - Satellite Navigation TomTom is the answer for road navigation in the car - but when there are no roads and you're on foot, hand held GPS devices are more useful. At midnight 1st May 2000, as a response to public pressure, the US Government finally removed the deliberate random error on GPS signals. Due to the US belief that their own system could be used by enemy military units against them, a error of around 200 metres was introduced. With this error removed, it is now possible to possible to find a location anywhere on the earth's surface with an accuracy of as little as two metres.
	I've already described the in car GPS devices. However, these kind of devices are little or no use if there's no road, and you're completely off the beaten track. Handheld GPS devices are more for relative position. They come into their own when you want to plot your journey from A to B, so you can find your way back again.
	Price was the main consideration in my choice of GPS device. I went for the eTrex hand held from Garmin. The eTrex costs less than Ł100, and when I also learned that it's accuracy is as good as most of it's bigger brothers I was well pleased! Find out more in my review of the eTrex