Central London Walking Map
From Headway Wiki
http://shortwalk.blog.co.uk/2007/02/09/think_outside_the_tube_download_central_~1707446
This map, posted by students on February 9, 2007, overlays walking times between stations on a map of the downtown section of the London Underground. Apparently, the walking times were all empirically measured over the course of a week.
