I use Fedora and the new XGL which leaves Mac OS X behind with miles, to install XGL just follow the steps described on the link above, and you can get more info here.
The original background is here (deviantart.com is down for the moment, so I can't give you a direct link, but search for helv and you will find it) and the flipped one I did is here. Big thanks to Dajno for the wallpaper!
You can get the icons from here, its a mix of the original OSX icons and the nuoveXT, so big thanks to Kiddo & Saki!
Note to icons: there is a directory called OSX/private/applications/usr which should be copied to the root / and overwrite everything if prompted. This is because some of the progrs don't support themeable icons.
The theme is a slightly modified Clearlooks-graphite theme by Lokheed's, which you can get it from here
That's all, enjoy :)