This tutorial shows how you can enable Compiz Fusion on an Ubuntu 11.04 (Natty Narwhal) desktop with the Unity interface (the system must have a 3D-capable graphics card which I assume it has because otherwise Unity wouldn't start, and GNOME would be used instead). With Compiz Fusion you can use beautiful 3D effects like wobbly windows or a desktop cube on your desktop.
This document comes without warranty of any kind! I do not issue any guarantee that this will work for you!
1 Preliminary Note
I have tried this on a desktop computer with an NVIDIA GeForce 8200. It should work the same way with all other 3D-capable graphics cards.
Your system might tell you that additional drivers (e.g. the proprietary NVIDIA drivers) are available for installation, but normally you don't need these. The installed driver should work fine and make the system use your graphics card's 3D features because otherwise the Unity desktop would not have started.
2 Installing AWN (Avant Window Navigator) And CompizConfig Settings Manager
The first thing we do is install AWN (Avant Window Navigator), a dock-like navigation bar for the Linux desktop. We use this as a fallback because when we configure Compiz, the Unity navigation and taskbar will disappear temporarily, making it impossible to launch any program or to log out of the current session (which we will have to do at the end to complete the Compiz setup). Once Compiz is configured correctly, you can use the Unity navigation and taskbar again.
Start the Ubuntu Software Center:
Search for avant in the search box. This should list the Avant Window Navigator package in the results. Click on the Install button to install AWN:
Next search for ccsm in the search box. This should bring up the package Advanced Desktop Effects Settings (ccsm) in the result list - this tool allows us to configure Compiz. Again click onInstall to install that package:
Afterwards, you can close the Ubuntu Software Center.