Looks like somebody else has tried to put up a fresh new theme inspired by the local population of the Mushroom Kingdom.  You have Mario, Luigi and the rest of the gang here.  I have to say this is a beautiful piece of work.  Makes me so happy I could go bust brick with my head until I find a surprise. 

There is a lot to love about this new Mario theme for Firefox.  For example:

This is not the first Mario inspired Firefox theme, there have been several others:

• Super Mario Bros 3 Firefox Theme
• New Super Mario Theme for Firefox 3

So you had better grab the MushroomKingdom theme before it gets taken down due to trademark concerns and Nintendo’s lawyers.  You can download the MushroomKingdom theme (while you can) via the Firefox Add-ons web site.  To check out more of the author’s Firefox theme work, check out his own site at savaden’s designs.

1-UP JUST FOR YOU!  Just in case it gets taken down, I’ll go ahead and host a mirror here of the MushroomKingdom theme for you to enjoy.  Just unzip and then drop it into Tools > Addons > Themes.  Just make sure you beat Bowser there before he takes it to another castle.

If you want your Firefox surfing to be laced with a touch of class, go give Amethyst a look. I promise it is worth it.