As you likely know by now, Google has updated their favicon.ico from the boxed G ()to a lower case (with no box) g (). However, Firefox continues to use the old icon in the search bar.
Old Google Firefox Search Bar
New Google Firefox Search Bar
To switch to the new icon in your Firefox Search Bar, keep reading.
To update Firefox and force the search box to display the new icon, download and install the Add to Search Bar Addon (previously reviewed here) – which works in both Firefox 2.x and 3. As with all Firefox addons, you’ll need to restart Firefox after it’s installed.
Now visit http://www.google.com. Right-click (ctrl-click for single-button Mac folks) in the Google Search box and select Add to Search Bar…
A small pop-up window will appear asking you to name (and select an icon) the new search. Leave the defaults and click OK
Now you’ll notice the new Google icon in your Search Bar.
To remove the old Google entry (and make the new one the default) select the arrow next to the new Google icon and choose Manage Search Engines… from the list.
First, select your new Google entry and click the Move Up button until it’s at the top.
Once it’s at the top, highlight the “old” Google entry and click the Remove button. When you’re done, click OK
That’s it – you’re done. Enjoy your the new Google icon in your Firefox Search box.