My basic idea is to find a kids toy with large, distinct buttons that can be pressed with a paw. I'll then gut that device and use the keys to interface with an Arduino. The Arduino will play back either a voice synthesized or prerecorded word that is associated with that button.
Words can be grouped to communicate simple ideas. eg. "Mom" "Food"
Tachyon
Alpha Charlie
Chris Perivolaropoulos
TinLethax
Kumar, Abhishek
UPDATE
I hit the resale shops today and scored an input device bonanza!
So the Turtle is out and the new toys will have to be sorted through while I figure out an arrangement of buttons and segments that will work best for the project.