A skyview of Manhattan with overlaid subway and rail lines. 7 Subway Extension, the first phase of the Second Avenue Subway, and East Side Access included.
Another fantastic aerial photo/subway routes mash-up from Arnorian – a companion piece to this very popular piece that shows more of New York and New Jersey.
What I really like about this is that you can make out individual buildings and streets quite easily – the Empire State Building is immediately obvious, for example – placing all the lines shown in a very real and recognisable context. I can definitely relate many of the locations that I visited on my trip to New York a few years ago to this view, which is kind of cool.