The basic idea here is that you can easily link to the wikipedia entry for a given topic by putting the [wikipedia]topic[/wikipedia] tag into your post. The tag is replaced by a link that executes the wikipedia search form for that topic.
The plan is to augment this with a mouseover popup containing an excerpt from the wikipedia page.

Wp-Wikipedia-Excerpt

This plugin replaces [wikipedia]topic[/wikipedia] with a wikipedia search link for that term.

tomknows

Displays a Micheal Jackson memorial badge in the sidebar of your blog via widget interface or anywhere else via function call. Make the people remember the King of Pop.

KingOfPop

Displays a Micheal Jackson memorial badge in the sidebar of your blog via widget interface or anywhere else via function call.

Wp-Wikipedia-Excerpt vs KingOfPop