I wanted to announce a new theme for Firefox (Windows & Linux) called macfox. You can find it here: https://addons.mozilla.org/firefox/3174/
macfox offers the clean look of Mac OS X FireFox on your PC and includes Aqua-style UI elements and enhancements that are quite accurate to the Mac OS X environment. The theme emulates the default OS X Firefox theme. A graphite version, a FF 2.+ version and maybe even a Safari emulation are down the road.
Linux users can go to the raw HTML page for macfox http://www.webether.com/macfox/
(actual webdesign coming soon) and install the .jar file from there.
screenshot from Windows XP SP2