Worldmapper http://www.worldmapper.org/ is a collection of world maps, where territories are re-sized on each map according to the subject of interest. The maps are warped to a size proportional to the statistic they are representing. For example, the size of the countries below is proportional to the number of malaria deaths in that country:
Worldmapper is a very useful teaching tool in Geography as students get an instant spatial feel of the location and distribution of a lot of statistical facts.
Adorngeo's Blog 