From MozillaZine Knowledge Base
The â€œGoâ€ toolbar button in Firefox 2.0 cannot be removed via the standard Customize Toolbars palette due to the way it was implemented. Until bug 347754 is fixed, this preference provides a stopgap solution to quickly hide the button.
Possible values and their effects
Hide the â€œGoâ€ button from appearing next to the location bar.
Display the button normally. (Default)
First checked in
Has an effect in