You can search for a string from the Location bar in Mozilla Firefox, like Google Chrome. Here is how to do it...
1) Open Firefox
2) Type about:config in the Location bar.
3) In the Filter box, search for Keyword.URL
4) Doulbe-Click it and you can edit it. Type http://www.google.com/search?q=
5) Hit OK and you are done. Now you can search from the Location bar in Google.