This isn't exactly what you are looking for but it might put you on the right track.
http://ubuntuforums.org/showthread.p...d+while+typing or
http://blog.technomancy.org/2007/05/...-the-trackpad/ ... the only other thing I came across was a third party software called SideTrack.
The only other two things I can think of is either emailing Apple about it or putting a sticker over it or something similar.