OS X: How to Use a Screen Saver as Your Desktop Background
If you are bored with your desktop and want to give it a little style, or if you just want to impress your friends, you can run a screen saver as your desktop’s background to liven it up.
1. Right-click on the desktop and select Change Desktop Background.
2. Select the Screen Saver tab.
3. Select the screen saver that you wish to run as your desktop background.
4. Close the Desktop & Screen Saver window.
5. Open Terminal.
6. Copy, paste and execute the following Terminal command:
/System/Library/Frameworks/ScreenSaver.framework/Resources/ScreenSaverEngine.app/Contents/MacOS/ScreenSaverEngine -background
7. Minimize the Terminal window.
Your background is now the screen saver that you selected in step 3. To return the background to your wallpaper, simply close the Terminal window.






Per Kristian Sørpebøl said on January 24, 2010
any way to keep it when closing terminal?
Anonymous said on March 10, 2010
I recommend using screen.
Type in terminal:
screen
[press enter again]
[the command above for the screen saver]
then you can close the window. To stop it you will need to type in terminal:
screen -r
[press 'Control-c']
exit
The last exit command closes screen, if you never turn off your computer then you will probably will want to make sure you exit it manually. (not that it costs you a lot)