Adwaita Cupertino Theme, the solution if you can't install macbuntu 11.10 - Ubuntu 11.10 (Oneiric Ocelot
Adwaita Cupertino Theme
It’s a Mac OS X like theme for Ubuntu 11.10 users. The theme is based on Adwaita, and the theme is designed by the user trastes.
Download Adwaita Cupertino Theme
It is based