With Sogudi, one can perform Google (and all other types of) searches from the main location field in Safari. As such, I prefer a minimalist address bar, and was disappointed I couldn't easily remove the Google field in Safari 2.0.
Poking around in Browser.nib (located in Safari.app: Control-click and choose Show Package Contents: Contents: Resources: English.lproj (or whatever language you're using), I met with failure. Then I found ToolbarItems.nib in the same location. By editing that nib file with Interface Builder, one can modify or remove the location and/or google fields to their satisfaction. The Developer Tools must be installed to do this...
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050503102401592