Get one of these 3 SDL screensavers:
On Windows, run the executable to install the screen saver.
For Unix, download the swf file and use xscreensaver and the stand alone flash player. Macromedia's stand-alone Flash player has xscreensaver support, as of version 6.0.79 and later. To use it, put a line like this in the programs preference in your .xscreensaver file:
"My Flash" gflashplayer -root $HOME/swf/my_flash.swf