Satire

Satire is the ridicule of human vice and folly; it has served as a standard tool of propagandists throughout recorded political history. It is usually a defense against libel in U.S. courts. In any context, satire is by its very nature necessarily augmented with some message, depending for humoural quality on a shared axiom among the satirist and the audience. Propagandists use satire to reinforce ideas and to use inference to introduce new ideas.

- Web Satire

http://www.theonion.com - US spoof news site http://www.objectmonkey.com - UK crossover between Wired and Private Eye