Nvidia just released graphics drivers with a support for Optimus technology. This means that there is now a native support for swapping between two graphics cards (one being Nvidia, in most cases the other one being Intel).
Information about Optimus:http://en.wikipedia.org/wiki/Nvidia_Optimus
This is how you update your Nvidia drivers to version 319.12 (the current version at the time of writing) (NOTE: for Ubuntu-based distros):
sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update
sudo apt-get install nvidia-319 nvidia-settings-319
The new drivers seem to bring other changes as well. You can read the release highlights at http://www.nvidia.com/object/linux-display-amd64-319.12-driver.html