(Pocket-lint) - The Ordnance Survey is paid for by the tax payer - serveral times over as it goes. So, why is it that we foot a further fee to Great Britain's national mapping agency every time we buy a satnav or even an A-Z?

If you purchase a TomTom, approximately 20-30% of that cost goes to Tele Atlas who licenses the maps that TomTom and many other hardware manufacturers use. Part of that charge is because Tele Atlas itself, and the company's main rival Navteq, have to buy the data from national mapping agencies in the first place, like the Ordance Survey, and then stitch all the information together. Hence the consumer having to pay on a number of levels. It was this and many more nuggets of mapping gold that Pocket-lint picked up on when we stopped in for a drink with Steve Coast, the founder of the collaborative, free and editable world map, the OpenStreetMap.

The aim of the project is to bring to the mapping world what Wikipedia brought to encyclopedias. The main troubles with the current system are that it's expensive for the end user and it's inaccurate. Tele Atlas and Navteq know that they're inaccurate. They say so themselves. It's because they can only update the roads every 12-18 months when they send one of their vans round with a GPS to check. They also know that they're inaccurate because they put inaccuracies in on purpose to make sure people aren't using their maps without permission.

OpenStreetMap circumvents these problems by crowd sourcing the data rather than buying it from agencies. The data can then be passed on for free, in the true open source sense, and it's also constantly self-updated. The results are marked if you look at the differences between OSM and Google Maps with its Tele Atlas supplied information.

"Take London's parks for example," says Coast as he gestures to the city behind us. "On Google maps, there are no names on the paths going across Hyde Park and some of them appear to go through ponds and lakes. There's even one marked as a carriage way that you can drive down. The difference is that Tele Atlas uses vans to check their routes and they can't drive through Hyde Park. OpenStreetMap uses people."

It's not just the level of road detail either. The OSM community maps cyclepaths, hiking trails, pubs, recycle points, shops and even trees and lamposts. Users can add any level of information at all, it's just a question of which of it is displayed on the viewed copy.

"Think of the data we have as a soup and it just depends on which parts we call on for each map. You can use a section called the style editor to change preferences. So, a company like Virgin might want to change all the colours of the roads to red for their commerical maps. They can do that because there's complete access to all the data and the only restrictions are like those for Linux - you have to credit OSM at the bottom and send us any information on any improvements you make."

The system, of course, relies on the community being willing to do the leg work and that's perhaps where the comparison with Wikipedia ends. It's a lot easier to get someone to update an article from home than it is to send them out with a GPS. It also brings the community's location into account.

"Most of Africa, that's a black spot for us," confesses Coast, palms up. "That's the case for much of the Developing World. People just don't have the equipment, and in the UK, the Medway towns aren't so good for us. It's just very hard to get people interested in some places."

That said, if you take a look at what Google Maps comes up with for Africa, there's not a hell of a lot there either, and, in fact, choosing the city of Windhoek in Namibia and Zomba in Malawi at random, OSM has more to offer. Places of high conflict are also far better covered in OSM. They're the only agency to have maps of Baghdad. You wouldn't get many Tele Atlas or Navteq drivers volunteering for that job.

Germany has also been a huge success story for OSM. Although the term is relative, it will be the first country that the service considers "complete" as of later this year. There are huge numbers of enthusiasts in the country and they hold mapping parties of up to 40 people who'll turn up, get given a GPS device and return later that day when the group has covered an area. It's also a way to introduce people to the community and shown how to get the GPS data onto the system. So why do people do it?

"It's addicitive. People really get into it. A friend of mine described it as like dot-to-dot for stoners but it's more than that. There's a certain civic responsibility that people take on. They like to make things correct. There's something in the pride of getting your part of the map right."

But it's not just Europe who've picked up the bug.

"I was giving someone a demonstration of OSM on my laptop and asked them to name any city in the world. I was a little worried when they asked to see Havana, Cuba, but when we got there, we discovered an absolutely stunning map of the city - one of the best I've seen."

The project started while Coast was a student at UCL, who continue to host the OSM for free today. Orginally reading Computer Sciences and later switching to Physics, he found some time to have a look at a few of the university's gadgets.

"I was playing around in the VR labs with augemented reality and a got hold of a GPS device. I started plotting all sorts of points in space and then when I tried to put them on a map, discovered how many hurdles there were to getting the data."

He now lives in San Francisco where he's also started a more directly money making business in the shape of CloudMade - a tiling service that hosts the OSM maps more reliably than the UCL servers for mobile phone apps and other enterprises to use. In fact, if you go to the White House website, you'll see an OSM map there, as provided by CloudMade.

The brilliant part about crowd sourcing mapping data is that, unlike Wikipedia articles, there's less of a chance of bias. There's no opinion involved. Either a road is there or it isn't. The only issues have been over road naming in the disputed area of Northern Cyprus and the odd bit of accidental map graffiti.

So, what of the future of OSM? Where does Coast want this to go and exactly what's in it for him as the founder of a not for profit organisation with 150,000 active users?

"The plan is to overtake Tele Atlas and Navteq. It's coming for them and it'll hit them hard like it did for the guys at Encyclopedia Britannica when Wikipedia grew. I want OSM to become the biggest mapping service in the world."

Once positioned, such a company would doubtless sell for huge sums with so many location-based services, hardware manufacturers and end users involved. It's unlikely, that OSM will ever provide a Street View in the way that Google has with the need of so many millions of pictures to be taken on specialised cameras but Yahoo have already donated their satellite maps to help out and the third largest mapping service, behind NavTeq and TeleAtlas, AND, kindly gifted all of the Netherlands to the OSM in 2007, anything's possible. Coasy doesn't even rule out buying data, should it be the right deal. The other area in which the service can move would be adding reviews to the map annotations. Again, perhaps another company might save the OSM editors some legwork there too.

Whichever path it takes, it's easy to see how OSM can become an incredibly powerful player in software and services and on the internet as a whole. It's hard to tell whether the growing community will snowball quite the same way as it did for Wikipedia but there's certainly plenty of good reasons for Tele Atlas and Navteq to be looking over their shoulders. Roll on the mapping revolution.

Writing by Dan Sung.