X itself puts on this screensaver by default. You can check this with xset q
. To disable, type
bash:$ xset s off
X also automatically puts your pc in standby after 20 minutes or something, and it puts it into hibernate after 30. It would turn it off after 10 more minutes if it could. To disable this too, type:
bash:$ xset -dpms
You can do this automatically when you log in successfully by putting these lines in ~/.xsessionrc:
robo@anonymous:~$ cat .xsessionrc
# turn off default screensaver
xset s off
# turn off default standby, hibernate, ... after n minutes
The screen still goes blank after 10 minutes before you login, in gdm. But that doesn't bother me.
This was probably put in because of people with old monitors, that can have images burnt in to them. Or for energy saving purposes. Still a pain in the ass, though.
You can put it in Xorg.conf too : http://www.shallowsky.com/linux/x-screen-blanking.html