ALS and linux

[Peter Reed]

Hello everyone
I have a friend that has ALS (Amyotrophic Lateral Sclerosis) or Lou 
Gehrig's Disease and presently is using Windows XP which has pretty good 
support for this type of situation, however my friend would like to know 
if it would be possible for him to use linux.  He is unable to use the 
keyboard and has to use the mouse exclusively.  So my question is is 
there a distribution and/or software made for linux that you know of 
that would be sympathetic to a person in this situation.  He would 
really like to make the  switch.  Any info would be a help.  Thank you 
in advance.
Peter Reed