A few days ago the FBI requested help from the public to help solve a cipher found in the pocket of a cold-case murder victim. The body of the victim, Ricky McCormick, was discovered dumped in a field near St. Louis, Missouri back in 1999. Both the Cryptanalysis and Racketeering Records Unit of the FBI and the American Cryptogram Association have extensively analyzed the cipher and both have, thus far, come up empty handed.
The response to the request for help has been so significant that the FBI has created a specific page on their website where members of the public can submit information from their attempts at solving the cipher (which, for some reason, they've chosen to refer to as a "code" - a slight misnomer).
If you've been racking your brain trying to solve the Zodiac's 340 cipher and need a little diversity or distraction, you might try your hand at these. As for me, I going to have to pass.