I am trying to to set a global screensaver and blanking idle timout (with screen locking) that will affect all new user accounts. I noticed that gnome-screensaver in 12.04 when configured by a user, writes some data to a blob in ~/.dconf, but I have no idea how to set it globally. I also know that the global timeout is 10 minutes with blanking, but have no idea where this is set system wide. I find the whole dconf transition a bit difficult.

If it is not possible to configure gnome-screensaver this way, I would be quite interested in a solution with xscreensaver/xlock.

The purpose of this is to set a blank screen with automatic locking. Both because of resource usage and security.

Forgot to mention that this is a default Ubuntu 12.04 desktop install with Unity and LightDM. I will however install gnome-shell and gnome-session-fallback to let people choose. It would be nice if a solution works across different sessions.