London Congestion Charge Zone as GIS data

So, I ask Transport for London whether the London Congestion Charge Zone is available as a GIS file, and if not, why not? 

I get a letter back, telling me no, but asking if I have any suggestions. Wake up TFL!

If data be the food of science... (Entangled Bank EVO2012 Poster)

Here's a preview of the Entangled Bank poster for the Earth Virtual Observatory International Conference: Harnessing Emerging Technologies for Environmental Science, Royal Geographical Society, London, 16th May 2012 where I'll also be running a demonstration.

Click to download full size pdf