I own an old Dell Inspiron 4000 laptop whose trackstick / trackpoint (the blue little joystick in the middle of the keyboard) has become really annoying : typing on the keyboard, or even touching the surface of the laptop generate parasite movements of the pointer.

I've looked for a way to disable it, and found one way using hal (since X is auto-configured in Ubuntu now), by adding the following file as /etc/hal/fdi/policy/10-disabletrackstick.fdi :

<?xml version="1.0" encoding="UTF-8"?>
<deviceinfo version="0.2">
     <match key="info.product" contains="TPPS/2 IBM TrackPoint">
       <remove key="input.x11_driver"/>

Thanks to this post by Brice Goglin for he hint on how to disable a device.