I don’t use xscreensaver (or for that matter gnome-screensaver, which is rudimentary at best). That’s because I’m an Openbox fan, and the idea of an additional daemon running in the background, waiting for me to do nothing … well, it offends my sense of efficiency.
So I live without it. But to be honest, the default X timeouts under Edgy are way too long. I think the screen times out at 10 minutes, and the backlight is powered down at 30. I’m not 100 percent sure on that since I can’t find what sets them, but those numbers seem right. They’re very long.
If you want to set them to something shorter, you can use xset dpms from a terminal, but that won’t hold on reboot. Editing your xorg.conf file is a better way.
Under the “Monitor” section, add this:
Option "DPMS"
And under the “ServerLayout” section, add these lines:
Option "BlankTime" "3"
Option "OffTime" "5"
Those variables set the time in minutes it takes the screen to go blank, and the time it takes for screen (or in my case, the laptop panel) to be turned off completely. Restart X, and see if you like the results.
There’s a more extensive (though slightly dated) explanation here.
Motho ke motho ka botho 
why? isn’t “xscreensaver-demo” a better solution? after typing this command you are given a full set of choices with those mentioned by author included…
That’s kind of my point: I don’t want another application running in the background. Installing xscreensaver adds another process to a system I’m trying to keep light. And since the screen timeouts for X are flexible, I’d rather use them.
xlockmore ? 🙂
I happen to use slock to lock up my computer in a key chord. You may want to use it and just take a look at suckless.org anyway.
for those using hotplug, the commands that will do the same (function) is:
# set X black out times (300 seconds)
xset +dpms
xset dpms 0 0 300