One of the small annoyances I have with Firefox is the default URL used for the Google search plug-in.  While I generally just type in a search term and hit enter, I do sometimes just hit enter without a corresponding search term just to get sent to the main Google page.  Why do I do this?  Mainly so that I can view the updated Google logos when they change for holidays.

With a default installation of Firefox the default Google page is the Mozilla Firefox Start Page.  While this is nice from a corporate branding sense, this special page does not have the links to either iGoogle or the Google Accounts login page, nor does is feature the often customized Google logo.  Also, none of the other search plug-ins that I have tested in Firefox exhibit a similar “feature”, they all dump you at the default page for that particular service.
Here’s how to change all of that.

Firefox 2.x for Mac OS X

1. Quit Firefox.
2. In the Finder, navigate to /Applications
3. Right-click (or control-click) on Firefox.app and select Show Package Contents from the context menu
4. In the window that comes navigate to Contents -> MacOS -> searchplugins
5. Open the file named google.xml in your favorite text editor
6. Change the value for the XML attribute named SearchForm as follows:
   

   Default:  <SearchForm>http://www.google.com/firefox</SearchForm>
   Changed: <SearchForm>http://www.google.com</SearchForm>

7. Save the file and start Firefox.

Firefox 2.x for Windows

1. Quit Firefox.
2. In Windows Explorer open the following directory C:\ -> Program Files -> Mozilla Firefox -> searchplugins
3. Open the file named google.xml in your favorite text editor
4. Change the value for the XML attribute named SearchForm as follows:
   

   Default:  <SearchForm>http://www.google.com/firefox</SearchForm>
   Changed: <SearchForm>http://www.google.com</SearchForm>

Voila!  Now you have what many of my friends would have logically concluded as the expected action for the Google search plugin for Firefox.

Note that this mod will have to be changed for each successive update of the Firefox application, so it may not be to your taste.