craftgrrl | Decorating A Shadowbox Frame

I have a question for everyone. A while back I went and saw Jensen Ackles perform in the play A Few Good Men and while there had him sign my Supernatural cover box. I also took a fair amount of photos of the boy. When I got back home I placed the cover box in a shadow box frame to display. I also trimmed down six photos of Jensen to frame it will but I am not sure how to adhere them to the shadow box (craft tape is not working I wake up in the morning and all the photos have fallen off), I am afraid to use glue because it my ruin the photos which would be a shame. Quite frankly I would like to decorate the entire back of the shadowbox to match its contents but I am not quite sure how to go about it. Does anyone have any suggestions for not only adhering the pictures but maybe jazzing up the box itself? I would be forever thankful. I am posting a picture of the shadowbox. Thanks for the help.