Jeffrey Heer, a professor at Stanford, has a some neat data visualizations on his web site.  They are part of a nice story he co-wrote in the June issue of the Communications of the ACM about different ways to visualize data.  On his site, you can manipulate this graph below and see the rise in obesity over the past 13 years.

You can read Mr. Heer’s full story here.

Obesity Cartogram

Obesity Cartogram