Update: So to get these to work properly with the key assignments you need
to change the script as follows:
(note, it you tried "sudo modprobe -r psmouse" from a terminal and it didn't
work, this will not help you. If you tried it instead from the alt+f2, this
may still be an option.)
---------
script 1:
#! /bin/bash
modprobe psmoue
----------
script 2:
#! /bin/bash

modprobe -r psmouse

--------


Save script 1 as mouseon.sh and script 2 as moueoff.sh
copy the two scripts into /usr/bin with sudo priveledges
run "sudo chmod +x mouseon.sh" and "sudo chmod +x mouseoff.sh"

run "sudo mouseoff.sh" to test the script and see if it works.

go to system -> Preferences -> keyboard shortcuts -> add
1)type in name of your shortcut "something like turn mouse on" etc.
2) in command, put "gksudo mouseon.sh" then ok.
3) repeat above for mouseoff.sh then assign each to a different shortcut.

for some reason if you put the gksudo 'in' the script, it throws an error on
mouseoff.sh complaining about the "-r" tag. You only see the error if you
run it from terminal.