SearchBox Sync is an add-on for Mozilla Firefox. It automatically updates the search bar with your search text whenever you search from a web page directly. The most common search engines (Google, Yahoo!, Live Search, YouTube, ...) are automatically synchronized, and custom rules can easily be added for those that are not detected.
If you like this add-on, you will probably want to try SearchWP.
Please visit my personal web site to contact me. Thanks for your interest. Georges-Etienne Legendre