Fantastic statistics at Gapminder.org

There is a set of amazing statistical animations showing national population trends over the past 50 years.

One of the smartest pieces of graphical presentation I've ever seen.

Here's an example

http://www.gapminder.org/downloads/flash-presentations/has-the-world-bec...

But once you get the hang of it you can correlate diverse trends such as life expectancy vs average income etc.