The folks at WebUpd8 noted that a developer on DeviantArt posted a wonderful new theme for Firefox 3.6xx called Elementary v3.0. Below are screen shots of it in OSX and Shiki themes. Below is the link where to get it.
Original article: http://www.webupd8.org/2010/10/elementary-firefox-theme-30-released.html
You can get the Firefox Elementary 3.0 Theme here: