[R] Creating the Firefox Download Analytics Map in R

[Jason Rupert]

By any chance has anyone put together the R code for reproducing the Firefox Downloads Analytics Map in R? 

Here is a link to an example: 
http://www.knitwareblog.com/wp-content/uploads/2008/06/firefox-3-download-map.jpg

I'll try to track down the inputs, but I am interested in putting the code to produce this or something similar. 

Any hints about the best packages, or references to R Blog posts that may discuss the code necessary to produce this or a similar plot is very much appreciated.  

Thanks again for all the insights and feedback.