Make any pages' search functionality available in the Search Bar (or "search box")...
Jump-to-word buttons and highlighting for the search box content
Enter searched words in the Firefox search box to sync when you search in web. In addition this add-on has automatic learning function.
Whichever web page you visit, use this tool to search over linked content. Just click the "G"-with-chain-link icon in your status bar to open or close the toolbar (or ctrl-alt-s). Great for searching from tables-of-contents, bookmarks, or blogs!
WebReview enhances the abilities to re-find already visited websites and visualizes every single browsing session based on your local Firefox history. Furthermore it proposes you regularly visited sites just in the right time.
Compare Bing, Wolfram, Wikipedia, Delicious, Stumbleupon with Google side-by-side, get the best of these very different search engines, content providers, and social bookmarks