Below are links to a series of funny (to varying degrees) Venn diagrams of the Republican presidential candidates by Matt Glassman.
Gingrich: http://www.mattglassman.com/?p=2167
Huntsman: http://www.mattglassman.com/?p=2177
Romney: http://www.mattglassman.com/?p=2193
Bachmann: http://www.mattglassman.com/?p=2208
Perry: http://www.mattglassman.com/?p=2232
Cain: http://www.mattglassman.com/?p=2255
Santorum: http://www.mattglassman.com/?p=2284
He has not yet done one for Ron Paul.
And if you've never seen Vice-President John C. Calhoun's hair, you should Google it.