Those inspired crazies at Mythbusters, Adam Savage and Jamie Hyneman, built a giant, working coding cryptex. The device was built for a demo at the RSA Conference, held at the Mascone Center in SF, in April. Now the pair is auctioning it off on eBay. Proceeds from the sale will go to the EFF.
You can watch a video of the demonstration at the conference here (unfortunately, it appears this video no longer exists). The auction page is here (action is no longer active and has been removed).