Open gedit and copy-paste the following lines into it:
#!/bin/sh
# This script disables the touchpad without disabling buttons by setting Hysteresis
# to an impossible value.
############
# Warning! #
############
# If you have a touchpad with no "Physical" buttons but have to tap the corners
# of your touchpad to simulate physical buttons, put a "#" sign in front of the next
# 4 lines!
synclient LTCornerButton=1
#synclient LBCornerButton=0
synclient RTCornerButton=3
#synclient RBCornerButton=0
# Set PalmDetect on: Needed if the before lines are commented away,
# Doesn't do any harm if they're not
synclient PalmDetect=1
synclient HorizHysteresis=10000
synclient VertHysteresis=10000
# Disable all other touchpad features
synclient VertEdgeScroll=0
synclient HorizEdgeScroll=0
synclient CornerCoasting=0
synclient VertTwoFingerScroll=0
synclient HorizTwoFingerScroll=0
synclient TouchpadOff=2
synclient LockedDrags=0
synclient TapButton1=0
synclient TapButton2=0
synclient TapButton3=0
synclient CircularPad=0
Then save it as /usr/local/bin/DisableTouchPad.sh
In a terminal type:
chmod a+xr /usr/local/bin/DisableTouchPad.sh
To activate it type:
DisableTouchPad.sh
and test whether this works.
To make this change permanent, go to the dash, open "Startup Applications", click add, in the command type: /usr/local/bin/DisableTouchPad.sh and in the Name and Comment type anything that will remind you what this was about. Click add again.
Presto: a disabled touchpad with the buttons still enabled!
Best Answer
The failure to recognise the touchpad and fallback to identifying it as a PS2 mouse is due to the hardware using a new protocol and the manufacturer not releasing the specs so that a free driver can be written.
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/550625
The protocol has been mostly reverse engineered and there is now a fix involving a patched kernel module, but it isn't completely perfect (won't do multitouch) and hasn't yet found its way into the mainstream kernels. See the discussion for details. It also tells you how to do the patch if you feel brave enough to patch your kernel.
If all you want is to be able to quickly and easily disable the touchpad so you can type, then try setting up keyboard shortcuts as follows.
will disable the touchpad while
will enable it again. Being able to turn the touchpad on and off with a simple key combination makes the problem bearable while we wait for a better solution.