Date: 11/18/07 (Java Web)    Keywords: google

By default in Firefox you can type one or more keywords in the location bar. Firefox recognizes that it is not an URL and uses I’m Lucky search with Google search engine for version < 2; it uses Google search by name for Firefox version 2 and above. Here is how you can change it. 1. [...]

Source: http://blog.taragana.com/index.php/archive/how-to-change-firefox-location-bar-searching/