FackBore Effects for Mac

From bbum:

FackBore Effects is a System Preferences module that allows one to select a single screen saver to run on the desktop or multiple screen savers to run in the foreground (partially transparent over the desktop).
Foreground and background screensavers can be configured to automatically start at login.
Source is included.
AVOID OPEN GL SCREENSAVERS IN THE FOREGROUND UNLESS YOUR SYSTEM IS QUARTZ EXTREME CAPABLE! Even with QE, screen savers in the foreground can have an extremely detrimental affect to UI responsiveness.
Recommenations: Try Plasma Tunnel, IGS Twisted, or SpiroScales in the foreground. Euphoria works great in the background. Slide shows look neat, as well.
While this is freeware, tips are appreciated.