Hail to the pie chart

In graduate school, I was introduced to the work of Edward Tufte, a statistician and professor, whose specialty is the display of information. One point he makes in his books and lectures is that pie charts should not be used in cases where the breakdown is easy to understand without the chart. There's no reason, for example, to show a pie chart when the vote for class president is 85% Dave, 14% Ellen and 1% Steve. But if you go to this link and scroll down, you'll find a similar situation for which the pie chart was the perfect choice.