Eric Harshbarger's 13th party, EPP13: Your Lucky Day? will have a theme of "luck". It is currently scheduled to take place on April 13, 2013.
For updates check Eric's website: http://www.ericharshbarger.org/epp/2013/
Puzzles
Edit
A simple rebus puzzle was originally featured on the main page for the event http://www.ericharshbarger.org/epp/2013/teaser_v4.png.
