Firefox - the most customizable browser to date. A huge number of extensions make it into a kind of monster web, for which virtually every task under force. I will not hold holy wars, and recommend that you refrain from doing so, but simply ask: what extensions to further refine search you use Firefox? I myself use a portable version of the browser, and I have long standing constantly expansion Omnibar, can greatly simplify the work of the search bar.
This extension removes the usual search bar as unnecessary (as in Google Chrome), and itself a search engine on the Internet makes it much clearer. Not only do you get more advanced search mechanism, but also more compact browser that all navigation is concentrated in a single line.
In the plugin settings you can choose whether to display search results immediately, a number of results display form in which they show (in an enlarged two rows or in a compact, one-line).
Between search engines can be switched as fast as before - by right-clicking on the search icon in the address bar.
More convenient extension to work with the search in Firefox I've never met.
Set Omnibar: https://addons.mozilla.org/en-US/firefox/addon/8823.