What is the best kind of GPS system for you? This depends on what you intend to use it for.

Garmin 12 GPS is very good. There are various models of the 12, 12XL etc. They can be found for under $150. The altimeter is usually off but once you find your position, most of the time the map tells me what my altitude is. They have a pretty decent battery life since you rarely ever use your GPS for 12 hours straight.

The vendors selling GPS units are Garmin and Magellan, those are good brands and can meet your requirements quite well. There is a third player, Brunton (compass makers gone hi-tech). They make very reasonably priced GPS units with lots of bells and whistles. Garmin GPS records the distance travelled, speed, average speed, etc. Make sure you get good battery life and enough memory to be useful.

Mitac Mio 168 comes out well for my requirements but is more expensive, especially if you go for the tom tom mapping software too (voice directions when I’m out on my motorbike!)

Most of the functions on GPS of this sort you can get from a map. Maps on pure GPS are not as good as on a GPS/PDA but good maps for these are usually expensive. Some mountain rescue team members use PDAs with 1:25000 OS mapping data for recording search patterns etc.

You really need to look at your own plans – for instance, most backpackers use GPS to “confirm” their position, and …