You may have seen those scary maps of the United States that show thousands of aircraft over the country at any given time. Check out this page for a series of quicktime movies of flight pattern visualizations — a must for map lovers or stats addicts. They're part of a larger project called Celestial Mechanics. This was presented in 2006, so it's not new, but it's new to me.
This visualization, set to music, is particularly tranquil and hypnotic. If only that could be said for real air travel.