This page shows a series of very interesting maps, created by Mark Newman of the University of Michigan. He has maps of the US (excluding AK and HI) where the sizes of states are adjusted to represent population. He then colors them to represent the results of the 2008 presidential election.

http://www-personal.umich.edu/~mejn/election/2008/

There are some interesting maps on this page, including world maps:

http://odt.org/mcart/index.cgi?code=3&cat=1