Install Jupiter

Instructions for Ubuntu 11.10, 11.04, 10.10, 10.04: http://www.webupd8.org/2011/09/jupiter-applet-finally-available-for.html

sudo add-apt-repository ppa:webupd8team/jupiter 
sudo apt-get update 
sudo apt-get install jupiter

Jupiter comes with a useful script to disable and re-enable the touchpad/track pad, it can be ran using the following command:

sudo /usr/lib/jupiter/scripts/touchpad

Now all you’ll need to do is add this command to a keyboard shortcut, below are instructions for several desktop environments.

In xfce:

Applications > Settings > Settings Manager

Click Keyboard

Click on the “Applications Shortcuts” tab.

Click Add:

Here you will be promped with a new window asking for the command you wish to run, enter the following:

sudo /usr/lib/jupiter/scripts/touchpad

Click OK and it will now ask for a keyboard shortcut. Simply press the key combination you want to assign to disabling the touchpad (for example, I used Alt+F1) the keys you’re pressing will show up and the window will close.

You’ll now see the command and shortcut in the list and you can now press that key combo to disable the trackpad and press it again to re-enable it.

In Gnome:

In Unity:

bish bash bosh.