Shifty, when your boy has an semi-permanent address, post it.  I think it'd be real nice if we sent him some letters.  I lost a knee to an RPG over there in '03.  The emotional trauma is just as bad as the physical, and I can attest first hand that letters of support, even from strangers,  work as good as any medicine.  I'd be honored to drop him a line and maybe make his day a little better.  I'm damn proud of your son and wish him, you & yours the best. 
Hooah, 'nuff said.