Population pyramids

Although I think that population pyramids are most interesting when made for smaller communities, the website, World Population Pyramids, lets you see them for most countries around the world, from 1950-2030. I found the graphs for Vietnam, which has undergone dramatic change during that period, to be fascinating. While many are so symetrical as to make you question whether they measure male and female distinctly, Qatar had fairly lopsided results.

I wish we had this for US counties.