Today is March 14th, also know as 3/14, or 3.14. Think back to high school math class, does 3.14 look familiar. That's PI... 3.14159.... and it goes on and on forever. How will you be celebrating? Wearing your favorite PI shirt? Sharing PI stories on Facebook? If you need a little help planning your PI Day celebrations, there is a site that can help you do just that. Check out PIday.org for PI souvenirs, rap videos (yes, really, see below), and more.