Read about
Metisse just yesterday. A new approach to fancy/3D-Desktops by Mandriva. Unlike compiz, metisse has features that let you actually use windows in transformed status. Mandriva has some videos (Edit 2016: link down,
archived version and
videos on youtube) that show you some of the features.
As you may already have expected, I couldn't wait to create some ebuilds, so fetch my overlay (which is still called xgl, but don't care about that) for fancy x stuff and run
emerge metisse:
svn co https://svn.hboeck.de/xgl-overlay
At the moment it requires it's own X-Server (very much like luminocity or xgl in the past), the window and composite manager is a modified variant of fvwm. After installing, run
Xmetisse :1 on one console and on another one
metisse-start-fvwm -wd :1. You'll get a fancy new desktop inside a window.
At the moment it very much looks like a design study, not really intuitive to use, but it has some interesting approaches. Nice to see that the linux desktop is evolving. For all non-gentooers, Mandriva has a live CD for you.