How to enable Compiz Fusion in Ubuntu

In Ubuntu Hardy Heron, Compiz Fusion is already installed and is automatically enabled after you have installed your graphics' card drivers.

The only thing you have to do is to install the Compiz Configuration Settings Manager.

Open a terminal and type: sudo apt-get install compizconfig-settings-manager
After that navigate to: System --> Preferences --> Advanced Desktop Effects Settings

and there you may enable/disable any plugin you want.