Are you ready?

Ice cube tray available at Think Geek.

Too late to shop?

There are online cards at piday.org:

The San Francisco Exploratorium

is celebrating their 22nd annual Pi Day:

Come create Pi puns, participate in Pi-related antics—and have a slice of pie

Activities, music, and stories at Teachpi.org.

The site owners have sorted through hundreds of ideas and chosen their 50 ideas best  for celebrating Pi Day. (Be sure to check out the Pi Day Carols, too!)