Firefox with Greasemonkey: Twitter Search adds real-time results from Twitter to the top of the Google search results screen—so you can see what people are talking about while researching a subject.
Once installed, simply search for any term in Google and you will see the last 5 tweets matching your keywords above the search results. When Twitter is down or has no results for your search criteria, the Google search results will look as they normally do.
Twitter Search Results is a free download, requires Firefox with the Greasemonkey extension. If you would rather rank news stories based on their Twitter results, you can do so with previously mentioned TweetNews.