Map data in the UK is not free. It costs money. Lots of money. Compare that with the USA where map data is essentially free.
Why? Well in the US anything published by the US Government becomes public domain – you can do what you want with it. You can buy maps from the US government for the cost of getting the data to you. In the UK the government is well known for taxing us as many times as possible, and it is no different than with maps. We pay our taxes so the Ordnance Survey can do its job and then the OS turn round and demand a hefty sum for us to buy the map data from them again (like I haven’t already paid for it through my tax!)
Well, there are a keen group of individuals who are creating world maps under a Creative Commons license. This means that you essentially have open source map data. They call this Open Street Map and it is a work in progress. They need help to get it completed. Every so often they have a mapping party where a group of people go out with GPS devices and record streets. They then upload that data in to a database, make corrections, add annotations (like the street name and type) and then allow it to be downloaded by anyone.
Their first mapping party in Scotland will be held this month in Edinburgh. So, if you have a GPS and would like to help create a free open source map that everyone can use, please get yourself along.
If you want to find out how to go about mapping, there is this handy guide to get you started.