3-D tube map
Not a particularly 
useful map and someone obviously has too much time on their hands, but it's pretty to look at.
Of course, a realistic picture of the tube should include:
- sweat rings (under the arms);
- grafitti (on the inside and outside the trains, including incising on windows, stations, lineside furniture, staff);
- empty fried chicken boxes (do people eat the bones too);
- 
squash balls
N.B. - I forgot to link back to 
Mike from whence I got this link.  Sorry, Mike.  Bad netiquette.