If you're one whose search results lead you to a Wikipedia page nine times out of ten, you would do well to install the Googlepedia extension for Firefox.
This free, terrifically easy add-on pulls the Wikipedia article most closely associated with your search term into the right half of a Google search results page. Modest controls let you expand, shrink, or hide the article.
Here's the best part: clicking a link within the article feeds the term back into Google's search engine, and therefore back into Googlepedia's cycle of serving up Wikipedia articles.
Googlepedia will undoubtedly save you time if a quick search is all you need. If you're one to submit to Wikipedia's siren call of never-ending knowledge, download at your own risk.