You know, every time I see a soldier in an airport---and if it's not intruding or too embarrassing for the person---I go up and shake his or her hand and thank them. I'd give them each a book, but soon would be on the street with the Katrina victims. So I give them a card and tell them, "This book is about YOU."
I've even had some write me back and tell me how grateful they were for people to stand up for them back home.