If you are interested in the history of philosophy, you may be interested in this social network of historical philosophers that has been making the rounds recently.
http://drunks-and-lampposts.com/2012/06/13/graphing-the-history-of-philosophy/
It seem that they used Wikipedia as their datasource, so there are some odd things based on current American political debates (like Leo Strauss being larger than St. Augustine, and Murray Rothbard being larger than Locke and Hume), but in many ways it maps the relations among philosophers remarkably well.
Chris
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