Thanks to James Thornett for pointing out this wonderful tool. MapTube allows you to select any two or maps and combine them, so: “For example, to see a map of the London Underground overlayed on top of a map of population, go to the search page and enter the keywords “tube” and “population”. Then click on the two relevant maps to add them. They will be displayed when you click on “View”.”

Not only that, but you can add your own data and combine them with others too, something which the BBC – James’ employer – has done on user surveys on issues such as the credit crunch and anti-social behaviour.

If you manage to have a play, let me know how you get on.