We all know about Google Maps and how brilliant it is. It’s gone from simple online mapping website, to an essential tool for mobile phones, complete with satellite photography, your friend’s location (Latitude) and, of course, the extremely groovy Street View.

But it’s not the only free mapping tool around, and not even the best, as I’ve been finding out over the past few months. The OpenStreetmap is a venture, started in 2004 by Steve Coast, similar to Wikipedia, only with maps.

His idea was that rather than rely on corporations with big budgets and teams of cartographers, or national institutions to generation mapping data, he would get the internet community to build up its own using GPS traces and donated satellite imagery.

I remember looking at it three years ago and being distinctly unimpressed at the level of detail. But, it’s improved beyond recognition, with maps of London, in particular, that are just as detailed, if not more so, than Google maps. And as time goes on, its accuracy and usefulness can only increase.

The really great thing about it though, is that the underlying map data is both free to use and manipulate. It comes under the Creative Commons Attribution-Share Alike 2.0 licence, and that approach is gradually beginning to bear fruit in the most wonderful of ways.

There are people working on all manner of projects, all across the world. There’s the OpenSeaMap project, aimed at mapping the shipping lanes and the like. Freemap is being developed for hikers in the UK. OpenRouteService.org is aimed at providing routing services, for cars, pedestrians and cyclists.

The most impressive, however, has to be OpenCycleMap.org, created by Andy Allan here in the UK. This boasts a cycle-specific view of the standard OpenStreetMap data, overlaying useful stuff such as where national and regional cycle routes are to be found, and where designated quiet routes run. It’s absolutely invaluable if, like me, you cycle a lot in town and don’t like sharing your ride with lorries and buses.

The open source nature of the OpenStreetMap and OpenCycleMap.org data means that it’s not only available online, though. It can also be repackaged and reused offline too.

The data’s already been re-engineered into Garmin-compatible format, so owners of eTrex and other recreational Garmin GPS units can download maps onto their devices for free. See here for links to the map files. There are even applications (mkgmap, for example) that let you generate your own Garmin-compatible maps, direct from the OpenStreetMap data.

And once you’ve got the maps on your device, there’s a whole host of other services to help you transfer routes and training data to overlay on the top of the maps. BikeRouteToaster uses OpenCycleMap to let you plan routes and then download those routes directly to your device, while GPSies focuses more on route-sharing. GPSies offers Google Maps as well as the OpenCycleMap for planning purposes.

I can’t help but be excited by all of this – and every week that goes by seems to throw up some another interesting development or avenue to explore. It can’t be long before some clever clogs somewhere produces a proper turn-by-turn in-car satnav application based on the free mapping data. Perhaps they already have…