Assuming you know how to edit your xorg.conf, there's a description parameters that define your touchpad's behavior at the bottom of this page for synaptics touchpadshttp://gentoo-wiki.com/HARDWARE_Synaptics_Touchpad
Rather than sudo the file every time to open and save it you can just add one paramter in the xorg.conf in the touchpad section:
Option "SHMConfig" "on"
This will allow you to use the command line to edit the parameters of the touchpad...
Once you've added this to the xorg.conf, save this and restart X
Use "synclient -l" to list the current settings (that's a lowercase 'L')
Adjust the settings as you see fit...
For instance, "synclient TouchPadOff=1" turns the touchpad off
Hope this helps
I need to get around to putting feisty on here