The TI-83 result got me stuck in a wikihole in which I learned about this flag, which is a color coded representation of an HD-DVD decryption key that the MPAA tried to sue off the Internet.

Internet users began circulating versions of this image, calling it a Free Speech Flag, in blog posts on dozens of websites and as user avatars on forums such as Digg. The RGB encoding of each of the five colors provides three bytes of the 09 F9 key, with the sixteenth byte "C0" appended in the lower right corner.[47]

The attacks on DVD security aren't really cryptanalysis, in a classic sense, but they certainly involve an angry mob - angry enough and large enough to have a flag! The future will hold more and more interesting examples of this sort of cultural phenomenon.