Realistic subway maps
I recently wrote a post about free subway maps. As we all know, good subway maps are a visual guide to the system and not by any means an accurate map of the real city. What seems close on a tube map could very likely be a large distance in the real world.
While widely acknowledged as a design classic, the tube map of London bears very little geographical relationship to where the stations are. Rob Gardiner has a page where the tube maps are overlayed with satellite photos of the city, providing a nice visualization of how the tubes actually are arranged.
What would a street map look like without the streets? Have a look at this map of London where the street names are removed.
I think that schematic subway maps are essential to any traveler using the system, but it is always good to compare them with real maps instead of getting the wrong orientation in a city.