A very compact & highly customizable theme that minimizes space consumed by menu & tool bars without hurting the overall usability. Supports Windows, Mac & Linux.
Theme based on the Nuvola icon set by David Vignoni (http://icon-king.com/?p=15).
MicroFox is LittleFox, but with retro/micro 8bit graphics. Smallest theme there is for all.
Install the About Home Themer extension to also theme the about:home page.
A combination of the Firefox 1 default theme "Winestripe" and the Firefox 3 default theme "Strata". StrataStripe is basically the Strata theme with Winestripe buttons. Looks much better.
An exotic yet exquisite alliance of blue and brown and a most soothing and calming theme for a pleasant browsing experience.