Well, this isn't a poster countdown, but it is a countdown nonetheless. We did jellybeans in a jar...eat one a day! Also a fellow diser put up mickey heads (paint chips from home depot) on her sliding glass door and takes one off a day. And along the lines of that, since you were asking about a poster and this just came to me with your idea of a poster combined with the other diser's mickey paint chip head idea..how bout a disney pic/poster that no one sees ahead of time covered with the mickey paint chip heads in random order numerical order. Number the heads...take off heads in decending order to reveal pic/poster underneath. Kind of like a advent calendar. HTH. Have fun! Michelle