Good way to make color coded map graphics? [View all]

Anybody know a good free or cheap way to make color coded maps of the world countries or the US, or Europe, or Asia, etc.?

It would be based on a data set that is stored like this:
name:value

I was on wikipedia looking at this page:
http://en.wikipedia.org/wiki/List_of_countries_by_life_expectancy
http://en.wikipedia.org/wiki/File:Male_Life_Expectancy.png

I followed the link in the image description and found it had been created using GunnMap at http://gunn.co.nz/map/.

Anybody used that tool?
What's a better tool for creating these images?

Any any info appreciated. thanks!