It won't come around again for another 100 years, so go out and eat all the pi(e) you want on March 14, 2015 to commemorate the first five digits of pi, 3.1415.
Get your geek on by reading Scientific American's special report: The Pi Day of the Century
Watch Star Trek's Dr. Spock and Captain Kirk get psyched about pi HERE in thsi 30 second clip.