NY Magazine picks the 22 Ingenious Ways to Improve the Subway from this tumblr list (some more practical than others).
Transit Maps. Designer Cameron Booth's blog and review of transit maps, diagrams, design and artwork from all over the world. [more inside]
Fabulous images of the Moscow Metro underground, also known as "the people's palaces". Click "M"s on the entry map to view gorgeous (often architecturally surreal) panoramic images, and visit the picture gallery for sweet details. Via Jorgen at Viewropa.