Xscreensaver. The documentation on xscreensaver's website DOES actualy work, however your Gnome settings can override what you tell xscreensaver to do using xscreensaver-demo. Gnome & xscreensaver dont' really get along all that well.

The xscreensaver program waits until the keyboard and mouse have been idle for a period, and then runs a graphics demo chosen at xscreensaver - extensible screen saver framework, plus locking.
The xscreensaver program waits until the keyboard and mouse have been idle for a period, and then runs a graphics demo chosen at.
For an Arch Linux branded experience, install the xscreensaver-arch-logoAUR package. This little tutorial is intended to help a Linux newbie to do something fun and hopefully learn some. sudo apt-get install xscreensaver xscreensaver-data-extra xscreensaver-gl-extra rss-glx xscreensaver-screensaver-webcollage. The xscreensaver program waits until the keyboard and mouse have been idle for a period, and then runs a graphics xscreensaver - Man Page. extensible screen saver and screen locking framework. xscreensaver with support for showing image descriptions in glslideshow.