I have a laptop with 16:9 screen ration. Sometimes I need to attach it to a projector via VGA. The projector ratio is 4:3. I use System Settings->Hardware->Display and Monitor->Size & Orientation ...
Is there a solid way of using either X directly or KDM/GDM/KDE/Gnome to quickly switch between an external screen and modify the screen layout accordingly? I'm stealing the inspiration from Windows ...