20 years ago if you'd told somebody that you could give them their position on the face of the Earth, accurate to within 5 metres from a bunch of satellites 11,000 miles above their heads they would have looked at you a bit odd. Even 10 years ago when the technology was available for civilian applications a GPS receiver was beyond the reach of most people. Within the last few years however, GPS has really come of age for the non-military user. One of the companies at the forefront of the GPS revolution is Garmin, the makers of the eTrex which retails for around £130 and is available in most outdoor accessory shops and even Dixons have now jumped on the bandwagon.

Once you've inserted two AA batteries into the unit it'll take a little while to track the satellites it uses to calculate your position. This can take as little as 30 seconds or so with a good clear view of the sky. If you're indoors, it'll take a bit longer, or possibly not even get the satellites at all. This might be a disadvanage if you've just bought a 40 bedroom stately home and can't find your way to the bathroom, but for most of us not being able to get a signal indoors isn't going to be much of a problem.

One of the most important features that any GPS can have is the ability to store waypoints. This is simple on the eTrex. Hold the Enter button down and you're given the chance to store your current location with a name of up to six characters or you can just plump for the number that the unit has automatically given the waypoint for simplicity. Whilst this may seem like the best option at first, realising that you've got a load of waypoints from 001 to 052, which relate to various parts of the country is likely to cause headaches. Sadly, the lack of a keyboard means that you have to scroll through A-Z and 0-9 plus a few punctuation marks to get the name right. The waypoint can then be plotted on a map or you can set the eTrex to direct you back to the waypoint. Up to 50 waypoints can be linked together to form a route with a large friendly arrow on the screen pointing in the direction you need to take as you approach each waypoint with the unit giving you straight line distance and approximate time to arrival at the next waypoint. If this has been well planned then it is possible to just leave the GPS in your car and take a quick peek at each junction. The arrow is large enough to be seen without having to look too hard and, as I found out one night on my way to a village I'd never heard of, if it's been planned well enough then the navigator (me!) can have a kip whilst the driver carries on in the knowledge that they aren't lost. On the subject of travelling, the unit works fairly well in most cars, although heated windscreens block the signal rendering it useless.

Various accessories are available for the eTrex, possibly the most useful of which is the PC link cable. This allows you to do many useful things, such as setting waypoints and a route on your PC before you leave home and uploading it to the GPS. This can be done by simply pointing and clicking on a map contained in Garmin's own MapSource software which is available in various different versions, pricing starting at around £45. Other software is available, including some free software which, although doesn't come with maps like MapSource, does allow you to key in the details on your PC without going through the painstaking process of setting up 30 waypoints using only the up and down buttons on the receiver to set a 10 digit grid reference and save the waypoints to your harddrive should your GPS suffer a mishap, and you forget the location of your mound of buried treasure/fishing spot/romantic hidey-hole. The PC lead can also be used for updating the GPS's built in software, updates are available from the Garmin website.

I've been using the eTrex for a few months now and my only real complaint is that the buttons can be awkward to use unless you have fairly small hands. Many people may not find this a problem, but I have found it annoying enough to deduct one star from it's overall rating. Provided you have a basic knowledge of how to read a map then the eTrex is a valuable tool and I don't leave it behind when going away.