Wherever you live in the world, on whatever continent, you are probably no more than a mile or two away from a 'geocache'. There might be one in the bush outside your home or on the corner of the street. There could be one surrupticiously attached to the road sign at the end of the street or glued to a fence by the video store.

They're everywhere, and most people haven't a clue about their existence.

But what are they?

A geocache is an item that has been placed somewhere in the world so that other people can find it. Sometimes they're canisters containing toys, a notepad and a pencil, other times they're just tiny capsules with nothing but a small roll of paper that you can sign to prove you've been there. Yet others are 'virtual'.

Geocaching is essentially a GPS enabled treasure hint game on a global scale where people both hide and seek the aforementioned geocache sites and log them on the Geocaching website for all to see.

Hiding a cache

For some, the thrill of finding caches is enough, but other prefer to hide some too, and this is where cunning and skill can take a part as you attempt to hide your cache so it's not too easy to find. If you're really up to it, you can also hide a 'multi-cache' and give clues as to the location of the other caches.

The location of caches is stored using your handheld GPS and then entered into the Geocaching website where people can search to find caches near them. When they've found ones that they want to go and seek, the GPS coordinates can then be downloaded to their GPS ready to be discovered.

As well as the GPS coordinates, there is also usually a clue as to the final resting place of the cache and a description of the location. Cache hiders are encouraged to explain a little bit about the local area to give potential visitors a little bit of insight into the place they are about to investigate.

The sport appeals to the geek in many because of the technology required to take part. Although some people have managed to find caches easily enough by using a map and a compass, the sport comes into its own when you use a GPS receiver.

The game is then like futuristic orienteering as the GPS points to the location, but that's not the whole story.

Alas, GPS sometimes isn't that accurate and this is confounded when caches are hidden in heavily wooded areas. This is where the clues come in and if the person hiding the cache has been particularly fiendish, they may have given a particularly cryptic clue.

Logging the cache

So, you've found the cache and you want to tell the world. Simply pop over to the website, sign in (or create an account) and you can now log the fact that you found the cache for all to see. It is also here where the competition element comes in and people try to out-do each other in the race to discover as many caches as possible.