This week I am giving a talk on some of the London maps that we produce in CASA. The hours of work I put in to such maps is minuscule compared to the amount of effort and time that the OpenStreetMap community have invested in producing a truly open (and often more accurate) map of London (and the rest of the world). To give an idea of just how far the project has come over the past five years or so, ITO World have produced a great visualisation (above).
As a bonus ITO World have also produced a similar visualisation for Berlin, Germany.

Thanks to Patrick Webber for the tip off about these.