.....if you like those maps of the world at night-time, where the urban areas glow brightly.....here's a map of all the world's flights, city-to-city, such that ATL and LHR glow brightest and you can contrast the "dark" areas with few flights.

(The maps don't sure actual flight paths, but just a city-to-city straight-line)
enjoy!

http://www.slate.com/blogs/future_te...wpisrc=flyouts