Can Gnome-Screensaver be set to only respond to the keyboard?

[Falcon]

I was wondering if there's an option somewhere to set gnome-screensaver 
to only "wake up" when there's keyboard input, as opposed to responding 
to mouse movement.  Would any of you know if this option exists, and if 
so where the appropriate configuration file is?  Or would this be 
something where I would need to modify the gnome-screensaver source code 
to my liking?