This is a simple extension for Safari 5.1 and above to enable keyword search from the address bar.
To edit or delete these, or add your own, right-click any web page and select "Keyword Search Settings". Here you can add keywords and search URLs, and delete or modify the existing ones. Put @@@ in the search URL to insert the search string, or use %%% if you want spaces to be encoded as %20 instead of +. It is also possible to have keyword expansions without search strings.
The url for the Default keyword is used when no other keyword is provided, and what is entered into the address bar doesn't look like a URL. This is set to Google's "I am feeling lucky" search by default.
Mac OS X 10.6
Mac OS X 10.7