The real London Underground

I go to London a couple of times a year, and often take the Tube to get around. The feature and the bug of the Tube map is that it's highly stylized -- great for calculating transfer points, but what you don't realize is two points a block apart may appear to be much farther apart when viewed on the map. Now I have The Real (London) Underground map -- a clever tool that morphs the stylized map into one that reflects the actual layout.