I have two really cool World War II posters. In each case, a G.I. took the poster down from the wall and made entries on the back for each day for a couple of weeks, and then mailed them to their wives. Like Ari's the posters are completely covered with tiny writing (that you can easily read) on the back, and it gives a cool insight into how life was for G.I.s in Europe in WWII.
I thought about trying to track down the owner (or their children) but there are only first names and a few clues in the writing. I really should contact History Detectives on them, because with their resources they might well find the owners (if they found them worth taking on).
I will try to dig them out to take photos.
Bruce