Nominal Area Choropleth map

The image above is a great example of a nominal area choropleth map.  Maps of this type represent nominal data in unrelated geographic areas.  Nominal data can be data regarding gender, race, class, ethnicity, etc.  This is a map of several European countries, and the colors have no rhyme or reason to them, they each represent data of that individual country.
http://web.cs.wpi.edu/~matt/courses/cs563/talks/nominal_data/geopolitical.gif