Lucid

Fastest Fox a.k.a Smarter Fox

Smarter Fox is a cool Firefox plugin, that helps you speed up your common tasks such as searching Google, searching Wikipedia, visiting bookmarks and much more. While searching google, it asynchronously loads the next page in google when you are at the bottom of the page, thus not impacting loading time. It adds a search bubble that pops up when you select or highlight a part of the text on a webpage.

https://addons.mozilla.org/en-US/firefox/addon/9825