CentOS - Jul 2008 - Power management and remote X sessions

I have about 50 CentOS 4.x/5.x stations running as thin clients.  So 
Gnome is running on the remote machine and the station is merely acting 
as an X terminal.  I would like to enable some power management.  I 
think I can control the monitor's dpms features and timeouts in the 
xorg.conf on the stations.  But if I want to have the stations 
themselves go into standby mode after a set amount of time, what would 
be the best way to accomplish that?

Thanks for any info,
Steve Bergman