This video (of which there are several copies on youtube) could provoke a lot of interesting questions. Where in the world receives the most air traffic? Why? How does this reflect historical developments? Does the spread of daylight hours affect flight concentrations? Which two continents / regions are the most connected by flights? Again, why? How does the perspective of a 2D map affect the apparent speed of flights in different parts of the globe? How else might this data be shown?

Thanks to my colleague Darren for passing this on.