You know what today is? Pi Day

Much excitement has been generated today among mathy types and, well, pretty much elementary school teachers because it’s Pi Day. (It’s also Albert Einstein’s birthday.)

If you haven’t made the connection between the date (3.14) and Pi, the ratio of the circumference to the diameter of a circle, you should get on over to the Facebook group for Pi Day and marinate in Pi-related humor, pics, songs and images of celebratory, delicious Pi Pie. (And maybe reconsider breeding.) Believe it or not, Pi Day predates the widespread use of the internet, and was invented in the 80s by San Francisco’s Exploratorium.

Totally feeling the math-centric love on Pi Day? There are shops that sell Pi-amobilia on the internet, including this one that actually transacts in units of Pi. (For instance, the ice cube tray above costs 3 Pi, or $9.42. No, I’m not kidding.) There’s also the standard Pi Day practice of baking and/or buying and eating delicious pies, and pretending that in some way makes you more math friendly.

Are you celebrating Pi Day 2011?