Office 2007 UI in Firefox
I usually don't do this, but i have to link to this article that explores possibilities of applying the Ribbon UI from Office 2007 to the web browser world. Unfortunately the author designed only one task (image shown below), but it shows the ever-growing interest in ribbon-based UIs.
To those complaining about Ribbon taking too much vertical space. This has been addressed at length in Jensen's blog, and you shouldn't take the screenshot above for a real product - just a prototype. The screenshot below shows Firefox alongside Windows 2007. Firefox here has the regular window title, the menu bar, the address bar, the bookmarks bar and a few tabs opened:
The second screenshot shows Firefox without the bookmarks bar, but the address bar uses regular (not small) icons and text labels: