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.

Slate Blank

Wiki Style Search will cause WP’s search to go directly to a page or post if a page or post’s title matches the search query; otherwise search results will display as usual. Plugin makes search function similar to that of Wikipedia.
For Example:
<ul>
<li>A search query of ‘spider’: http://thelargest.net/?s=spider takes you to http://thelargest.net/spider</li>
<li>A search query of ‘cruise ship’: http://thelargest.net/?s=cruise+ship takes you to http://thelargest.net/cruise-ship</li>
</ul>
Test more at <a href="http://thelargest.net" rel="nofollow ugc">The Largest</a>.
Please see more information at: http://thelargest.net/about/wiki-style-search-plugin
Plugin brought to you by <a href="http://slateblank.com" rel="nofollow ugc">Dallas web design</a> firm, Slate Blank.

Wiki Style Search

Wiki Style Search bypasses search results and directs users directly to an article if an article name matches their query.

Wp-Wikipedia-Excerpt vs Wiki Style Search