This plugin was written to automatically add links to wikipedia articles.
This is a very basic example. One second after the page has loaded the plugin will search wikipedia for any word of at least six characters. If the article is found the link is added, but only if the found result matches exactly. Live demo.
This is the latest stable version (1.01). Download the source.
Version 1.01
(2010-03-21) Added exactMatchOnly
Version 1.0
(2009-12-12) Initial release