Found at Boing Boing, from their guest blogger Charles Platt.

Population density has a long sociological history (c.f., Wirth’s Urbanism as a Way of Life) and is one of several factors that plays into discussions of land use, health, and population growth. This visualization presents an interesting start to spark a discussion. Is it misleading? What does it leave out? Does population density play a vital role in explaining human behavior?
