I just stumbled on this map that we first posted (via Digg) in 2008. The map may have used as its source the Central Intelligence Agency World Factbook, which in 2006 said this about The Axis of Medieval:
"At this time, only three countries—Burma, Liberia, and the US—have not adopted the International System of Units (SI, or metric system) as their official system of weights and measures."
We should point out that even these three countries do use elements of the metric system. And Burma's (Myanmar's) Deputy Minister for Commerce says his country is taking steps to adopt it officially.
For a look at the struggle to get Americans to think in meters, here's a story we ran on the sole employee of the U.S. Metric Program.
The Afternoon Map is a semi-regular feature in which we post maps and infographics. In the afternoon. Semi-regularly.