Touchpad-Indicator is a small indicator provides quickly enable and disable touchpad functionality in Ubuntu laptop and netbook. It is written by Lorenzo Carbonell and only supported in Ubuntu 10.10 Maverick now now supports Ubuntu 12.04, 11.10, 11.04, 10.10 and 10.04.

To install it, open up a terminal from Applications -> Accessories and run following three commands:

sudo add-apt-repository ppa:atareao/atareao
sudo apt-get update
sudo apt-get install touchpad-indicator

After installation, open the indicator from Applications -> Accessories -> Touchpad Indicator and set your touchpad in top-right via this icon: