Google bombing involves manipulating search engines' contextual search methodologies to cause a certain search phrase to point to an unexpected page, usually for comedic or satirical purposes. A recent example of a Google bomb happened in January 2008, when the search phrase "dangerous cult" returned the Chuch of Scientology home page as the top search result.
full story: http://howto.wired.com/wiki/'Google_Bomb'_an_Enemy
full story: http://howto.wired.com/wiki/'Google_Bomb'_an_Enemy