First install Sun Java(TM) JRE 1.6.0 (Mustang) in Ubuntu
The rest is easy, set up the repository for lookingglass:
## LG3D repsoitories
deb http://javadesktop.org/lg3d/debian stable contrib
# deb http://javadesktop.org/lg3d/debian testing contrib
# deb http://javadesktop.org/lg3d/debian unstable contrib
sudo apt-get update
Now to install the needed software from the repository:
sudo apt-get install lg3d-core
This will install lg3d, jdk and java3d.
You will need to accept the 3 licenses for lg3d, jdk and java3d to complete the installation, so if you prefer to use synaptic, keep the details button open!
Now log out and let gdm (not sure if kdm works) choose for the Lookinglass session, and you will see a beautiful 3D desktop!!
The installation was easy with a little help from this page.
Please read this to check if your video-card meets the needed requirements!!