Mac OS X GTK3 Tema Lion no Ubuntu 11.10

Instalação do cursor theme
Abra o terminal e execute os comandos:
wget http://dl.dropbox.com/u/47950494/Mac-Lion-Cursors.tar.gz
sudo tar -xzvf Mac-Lion-Cursors.tar.gz -C /usr/share/icons

Download do Tema:
mkdir ~/.themes
wget http://dl.dropbox.com/u/47950494/Mac-Lion-Theme.tar.gz
tar -xzvf Mac-Lion-Theme.tar.gz -C ~/.themes

Instalação dos ícones:
mkdir ~/.icons
wget http://dl.dropbox.com/u/47950494/Mac-Lion-Icons.tar.gz
tar -xzvf Mac-Lion-Icons.tar.gz -C ~/.icons

Instale o GNOME Tweak Tool com este comando (caso ainda não tenha instalado):
sudo apt- get install gnome-tweak-tool

Habilitar o MAC OS X Theme Lion
No GNOME Tweak Tool, na guia theme, configure:
Cursor theme > Mac-Lion-Cursors
Icon theme > Mac-Lion-Icons
GTK+ theme > Mac-Lion-Theme
Window theme > Mac-Lion-Theme

Fonte http://www.upubuntu.com/2011/11/how-to-install-gtk3-mac-os-x-lion-theme.html