I would like my touchpad to turn off when I'm using a mouse (or disable the touchpad altogether, since I always use a mouse) because it makes the pointer jerk around whenever I type. It changes my tabs and switches the place where I'm entering text. It is a pain.
How can I turn the darn thing off?
There is no such option under Shut Down>System Settings>Mouse and Touchpad
(there is no touchpad tab, see picture).
I use ubuntu 11.10.