Today, Aug 17 2011, is the 410th Birthday of Pierre de Fermat (17 August 1601 or 1607/8 – 12 January 1665) who was a was a French lawyer and an amateur mathematician whose early developments that led to infinitesimal calculus.
Google commemorated the 410th birthday of Pierre de Fermat by drawing a Google Doodle that demonstrating a class room board on which an equation is written with Google. When you hover your mouse over the Doodle the text comes up “I have discovered a truly marvelous proof of this theorem, which this doodle is too small to contain”.
He is recognized for his discovery of an original method of finding the greatest and the smallest ordinates of curved lines, which is analogous 
to that of the then unknown differential calculus, as well as his research into number theory. He made notable contributions to analytic geometry, probability, and optics. He is best known for Fermat's Last Theorem, which he described in a note at the margin of a copy of Diophantus' Arithmetica.
to that of the then unknown differential calculus, as well as his research into number theory. He made notable contributions to analytic geometry, probability, and optics. He is best known for Fermat's Last Theorem, which he described in a note at the margin of a copy of Diophantus' Arithmetica.via Wikipedia