wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | sudo apt-key add -
sudo apt-get update
sudo apt-get install virtualbox-4.1
sudo apt-get install dkms
wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | sudo apt-key add -
sudo apt-get update
sudo apt-get install virtualbox-4.1
sudo apt-get install dkms
sudo add-apt-repository ppa:webupd8team/gnome3
sudo apt-get update
sudo apt-get install gnome-shell-extensions-alternate-tab gnome-shell-extensions-alternative-status-menu gnome-shell-extensions-user-theme gnome-shell-extensions-workspace-indicator gnome-shell-extensions-apps-menu gnome-shell-extensions-drive-menu gnome-shell-extensions-system-monitor gnome-shell-extensions-places-menu gnome-shell-extensions-dock gnome-shell-extensions-native-window-placement gnome-shell-extensions-gajim gnome-shell-extensions-xrandr-indicator gnome-shell-extensions-windows-navigator gnome-shell-extensions-auto-move-windows
extensiones gnome-shell
Otra Pagina donde se explica como instalarlas: