This collection of entries is from November 01, 2006.
It's the Frost on the Pumpkin reminder to say "Rabbit, Rabbit!" as your first words of the day to have good luck! (or, if you blew it, before you go to sleep tonight, you can still try to get some luck, your last words have to be "Tibbar! Tibbar!")...
And for other derivatives to this meme, check out the alternatives: "White Rabbit" or Rabbit! Rabbit! Rabbit!.