disable touchpad when mouse is plugged in

[Doug]

I have some directions from "Just Another Lazy Blogger: Auto Disable 
Synaptic Touch in Ubuntu Hardy"
        
http://patanachai.blogspot.com/2009/02/auto-disable-synaptic-touch-in-ubuntu.html 

Anyway, this instruction was supposed to disable the touchpad when the 
mouse is plugged in.
Unfortunately, it was for an Ubuntu release named "Hardy" which seems to 
have been current in early 2009, and must have had some files that 
10.04.1 doesn't, like /etc/X11/xorg.conf and SHMconfig.  The 
instructions consist of modifying these files, and adding one.

Does anyone know how to do this in the current environment?

To any devs reading here:  this would be real nice to have as an option 
in the system. PCLINUXOS has it.

Finally, is all this going to be obsolete if and when I upgrade in the 
coming weeks when the next version of Ubuntu comes out?

thanx--doug

-- 
Blessed  are the peacekeepers...for they shall be shot at from both sides. --A.M. Greeley