OK, 3D Xgl is very cool and all of that. But is this something that we really need on Ubuntu and other distros?

To each his own, but I love eye candy. When I heard that you could get the 3D Xgl and Compiz environment running on Ubuntu/Kubuntu dapper (my default distribution), I immediately searched the web for instructions. Most of the instructions take a reasonably timid approach, which gets your 3D environment running in a test console (the second display, or :1). I’m more adventurous, however, and I immediately went for a total replacement. What follows are instructions for doing the same.
As the title says, these instructions are for Ubuntu/Kubuntu dapper with an NVidia binary driver. If you are using another distribution or are using an ATI card, you’ll have to adjust the instructions or look elsewhere for information. Sorry, but this is what I run, so this is what I know.
As I point out in the comments below, no screen shot can do this eye-candy justice. The fun is how windows boing into view, how they wobble when you move them, how the multi-desktop cube rotates, and so on. But I have included a snaphot file below that shows a terminal in the foreground, and Firefox faded into the background…. Source: Linux Journal