Set up Compiz Fusion 0.7.4 (included in Ubuntu 8.04 Hardy Heron)

Many people requested an update of my set up guide to the version of Compiz Fusion found in Ubuntu's latest release "Hardy Heron". From the beginning I was reluctant to do that, because the official current stable release is still Compiz 0.6.2 / Compiz Fusion 0.6.0.

So I decided to start from scratch... well not really, most of the new guide is based on the content of the "old" one.
But I decided it was time for a complete makeover. I hope it's even more easy to follow now: How to set up Compiz Fusion 0.7.4.