possibly noteworthy wrote:

19 cities in the world
with 20 million people
in the 21st century

This is Richard Saul Wurman's current project, at least since he sold TED to Chris Anderson. The information design of the site is excellent. Worth a look.

I agree, great site! It's interesting to see the ten largest cities from 1000 to 2005. I knew that Tokyo had the largest population today, but I didn't realize how much the population there had grown since 1950 (7m to 35m). The population clock is a cool feature, too.

RE: 19.20.21.