If you have a monitor that swivels to portrait or landscape mode, you can easily create shortcuts in Ubuntu that makes rotating screens via the Xrandr utility that more easier.
With a couple of application shortcuts on the Gnome Panel (see above), changing monitor orientation is literally just a mouse click away. The application icons: the left and right arrows indicate the direction of the rotation. You can find these icons under the directory below in Ubuntu.
My Ubuntu desktop is a bit unusual since I’m still using Gnome 2 and Ubuntu 10.04. You can add application launchers on other windows managers as well, whether it’s Unity, Cinnamon, Gnome or KDE, it doesn’t really matter which one do you use. Just use the following Xrandr commands below.
To default: xrandr -o normal
To rotate left: xrandr -o left
To rotate right: xrandr -o right
To rotate upside down: xrandr -o inverted
The application launchers I created just happen to be on my Gnome Panel. It makes changing my monitor orientation that much easier. I wished I did this a long time ago.