Where is xorg.conf in Ubuntu 10.04?

I'm in the middle of trying to setup dual monitors on ubuntu and would like to backup my xorg.conf...

The documentation I've been thus far say to do the following:

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf_backup

But I don't see the xorg.conf file anywhere... Am I missing something? Where is this located?


Quoting from http://ubuntuforums.org/showthread.php?t=1437980:

Current version of X.org don't use a xorg.conf by default but try to recognize everything automatically. If you create a xorg.conf it will be used.