CoolCollage features a screensaver that displays real-time generated collages. To use, select the "CoolCollage" screensaver from Window's display properties.

Using the "Settings" button will show the "Screen Saver" tab in CoolCollage. This will enable you to set how often the collage will update while in screen saver mode.
CoolCollage supports multiple monitors, so if you have two or more monitors connected, the screen saver will span the entire desktop area.