"For those of you teaching Cognitive Psych, this link might provide interesting stimulus material for a discussion on feature and structural theories of pattern recognition. It certainly illustrates that facial recognition may be possible even without facial features present (or that hair should be considered a prominent facial feature). "
While the PsychTeacher posting centered on Cognitive Psych, I as a psychology and history major, was excited to see something which could be used in a psychology or US History course.
For a brief article and graphic on the heads and hair of former presidents, go to http://www.nytimes.com/interactive/2010/02/15/opinion/20100215_OPART.html
For a similar article and graphic concerning the first ladies, go to http://www.nytimes.com/interactive/2009/07/04/opinion/20090704_opart.html