When Google, Yahoo, or any other major search engine overwhelms you with so many matches it reads more results than dollars in the national debt, ChunkIt might be the plug-in for you. Available for Firefox and Internet Explorer, it "chunks" up your search returns, providing snippets of relevant text.
The add-on splits your browser tab into two vertical sections, the left side with the ChunkIt results and the right with unchunked returns. Clicking on the text of a ChunkIt result loads the text in the right pane, highlights the relevant bit in yellow, and scrolls directly to it. A link at the top of the pane opens the page that your result lives on in a new tab.
This is a large plug-in, weighing in at more than 8MB. Using it requires use of the ChunkIt toolbar, something that may not go over well as browser design becomes more streamlined. Users who need help narrowing down broad searches will find this plug-in exceptionally useful. On the other hand, users comfortable maneuvering through "the Google" might find ChunkIt extraneous to their needs.