One of the most popular pin-up girl ever was Betty Grable. Her poster was ubiquitous in the lockers of G. I.s in WWII. Such photos often appear on calendars, which are meant to be pinned up anyway. Later, posters of pin-up girls were mass-produced. They became an instant hit. Even today you have so many calendars and photos made like the ones from the 40s. Here are some photos of the calendars which are waiting to be pined up on someones wall. Enjoy in this great gallery.