Ray Gun is a Quarts Screensaver for Mac OS X 10.5 and above. Download it below, extract the file, and install it by copying the file into
/Users/Your User Name/Library/Screensavers
Once you’ve copied it, it will appear in System Prefrences > Desktop & Screensaver > Screensaver > Other > Ray Gun 02 Screensaver.
Coming soon, Ray Gun for iTunes

Download Ray Gun 02 Screensaver