A few years ago I published a post outlining how to make nice-looking choropleth maps in R, and this piece still draws a reasonable share of my hits each month. Unfortunately, some of the techniques I used at the time are now quite out of date, and I was starting to feel bad for anyone taking my advice.
As of today the post has received a makeover, and takes a more modern approach.
For any returning readers, the changes are explained in a series of HTML
tags — which I have only recently discovered.