Another nice feature is that if your are using small icons on your navigation bar, your icons get turned into 16-bit versions of the larger ones:

This is not the first Mario-based theme for Firefox.  Do you remember that Super Mario 3 inspired theme?  It did not last long on Mozilla’s site.

With Mozilla’s history with copyrighted material based themes, I have to say it is probably only a matter of time before this one gets taken down – so grab it while you can.  Pickup and the Mario Bros theme at the Firefox Add-ons site.

Extra Life: Just in case it does get taken down, here is an alternative download link.  Just unzip and then drop it into your themes browser.