Here’s another map comparing the number of Toastmasters clubs in a state to the population.  Darker green means more clubs per 100,000 residents.  Interestingly, Minnesota (and generally the northwest USA) has the highest density of clubs, while the southeast has the lowest.  West Virginia has the lowest number of clubs per capita, and Kentucky and Maine are close behind.

This is as of 2007 census data, and July 2010 club data.  Unfortunately, census data for other countries is hard to get (not included with MapPoint anyway).