The "spinning cube thing" is called 3ddesktop... it looks even cooler in carousel mode if you have six or more virtual desktops.
sudo apt-get install 3ddesktop
(You need DRI enabled.)
to install the gl based x server:
sudo apt-get install xserver-xgl
You are using
ubuntu - always look to the repositories first.
http://easylinux.info/wiki/Ubuntu_dapper