To change the Screen Resolution in Ubuntu, simply type Display in the Unity Launcher and run the application. The snapshot of the Display application is taken from Ubuntu 12.10 and is also the same in previous versions also. Similar application is available in other Linux distributions.
But there is a handy command that can do the same thing even faster or can help you create a script (depends how creative and productive you plan to be). The command is simple:
This will display all the possible resolution profiles available for the current system (more can also be added and you can find help on http://www.x.org/archive/X11R7.5/doc/man/man1/xrandr.1.html).
To change to a known resolution:
xrandr -s 1024x768
And you have it! 🙂