Grandr is a GNOME Panel Applet that allow you to select screen resolution and orientation from your GNOME Panel.

It allows you to select screen resolution and orientation from you GNOME Panel. Unfortunately with my ATi X1400 I don’t have the option to choose the orientation of the Panel.

You can get a deb file from here

After you install it, select the panel you want to add it to, right
click and select “Add to Panel” then scroll thru the list and select
“Display Geometry Switcher”. A panel applet should appear