As the firefox 4 is finally out, one feature many of us would like to have is the integrated location and search bar like the way Google Chrome has. I myself do not like the idea of pressing a tab to go to the search bar or opening Google.com for each search. The Omnibar add-on for Firefox merges the url and search bar into one. It also gives search and url suggestions for the keywords as you type.
You may know that Firefox directly gives the search results if you enter two or more words in the address bar, but with this extension direct search is much simpler – one word search is also possible now.
If you want to search the same keyword on several search engines at once, you can give an advanced query like “<keyword> @g,y,b” which searches on Google, Yahoo and Bing in separate tabs.
Omnibar addon works with Firefox 3.5 and above and even compatible with the latest version 4.0.
Get Omnibar addon for Firefox.