Judge Smith ruled that the Da Vinci Code did not infringe on the copyright of the book Holy Blood, Holy Grail, and he issued his ruling with an interesting twist: He inserted his own code into it.
From the New York Times
Embedded in the first 13½ pages of the ruling is Justice Smith's very own secret code, one that when partly solved reveals its name: the Smithy Code.The code is contained in italics in the text of the opinion, which can be read here.
No one has yet solved all of the Judge Smithy code.
[Update April 28, 2006] That was quick - the code has been solved. For the answer see the Wikipedia Article on the Smithy Code.