Here are two graphics from the Wall Street Journal for Saturday, February 12, 2011. They each show top countries for either exports (right) or imports (left) for the United States. Note how nicely the data show current rankings of each country and their historical position in 1990 and 2000.

What is more, the relative volume of each country is porportional to the colored (gray, really) bars.

The graphs are easy to understand and allow the viewer to make comparisons quickly and accurately.

I think this is a marvelous example of how data can be displayed for meaningful interpretations.