I saw a link on yahoo earlier talking about how
www.ancestry.com has now digitized all military records up to the Vietnam war and that you can get info on family members for free until June 6 which is D-Day..
So I looked into it and sure enough, I found my grandfather's registration card for WWI from 1917....I knew that he lied about his age to get in and set his birthday to 1895 which at the time would have made him 21 years old...I know it was his card because I recognized his handwriting...
I also found out that he had a second middle name that even my mother didn't know he had because he never used it...
Try it out and see if you can find your people in the database.