Happy Pi Day!

Having begun in San Francisco in 1989 and spread since then, 14 March is now recognized as "Pi Day" in honor of pi (the ratio of a circle's circumference to its diameter) or the number that begins with 3.14159.  http://www.chicagotribune.com/news/local/ct-talk-pi-day-0314-20110313,0,7200698.story