Compiz is activated by default on Gutsy. To change the settings just go to..
System > Preferences > Appearances > Visual Effects.
If you want the more advanced effects, chose Extra.
This gives you some extra effects like the wobbly windows.
In order to fully configure compiz, you need an additional package called
compizconfig-settings-manager. Get it off synaptics.
Once you have this package installed, you will see a Custom radio button, which gives you tonnes of new fxs. Play around and have fun
Just remember you need a decent graphics card to enjoy all the advanced effects. It does take a toll on your system, but then nothing beats the envy on your friends' faces when they see your cool new desktop ;)