Disper-indicator provides a simple user interface for Disper display switching utility. Disper-indicator detects which monitors are currently connected to the computer and provides options to enable single screens, clone or extended screen configurations for systems having NVIDIA Cards.
Disper-indicator is based on Disper, an application written by Willem van Engen that lets you add and remove display devices.
Disper is an on-the-fly display switch utility. It is intended to be used just before giving a presentation with a laptop, when all one wants is that the beamer, which has just been connected, is able to show whatever you prepared.
Disper gives you the option to either clone all detected displays, or extend the desktop to them. Resolutions are automatically detected. For cloning, the highest common resolution supported by all displays is chosen; for extending every display device gets its highest supported resolution. For special setups requiring more detailed control, one can still use the standard display configuration utilities. At the moment only NVIDIA cards are supported and disper is specially useful for those who have installed proprietary drivers.
You need to add both Disper and Disper-Indicator PPAs. Run the following commands below:
sudo add-apt-repository ppa:disper-dev/ppa
sudo add-apt-repository ppa:nmellegard/disper-indicator-ppa
sudo apt-get update
sudo apt-get install disper disper-indicator
Note: I haven't tested Disper on my system as I have ATI graphic card. But this should work nicely with NVIDIA cards as many users have reported on Ask Ubuntu.
via Ask Ubuntu