The Fnorder is a neat shareware device for the generation of random messages from the Illuminati. Each time the Fnorder is run, it generates a random sentence or sentences conveying a usually surreal message. For example:
Dave Letterman is the amiable puppy; your evil twin originates from Sixth Street. Fnord.
Weird Al squeezes the white light bulb and the well-dressed yak. Fnord.
The Fnorder is available in Java, Perl, C, and WebSiphon, and is a fairly simple piece of code, yet creates addictively confusing output. It works by choosing a predefined sentence structure randomly, then filling in the "blanks" in this with randomly selected nouns, verbs, and adjectives, much like the creation of a story in one of those Mad Libs books.
Strangely, a Google search pointed out that the Fnorder is being used by some pr0n sites as an attempt to add more keywords to their pages - search for (NOT AVAILABLE AT YOUR CLEARANCE), one of its rather common output phrases, and you'll see a lot of them. They just get sneakier all the time.
The Fnorder is available from Steve Jackson Games at http://www.sjgames.com/misc/fnord.html.