We started making ours in 2004, and now it's in color, and now it's down to a 2-year calendar! It's different from the one that Skinner's friend made. This one is simply a big poster where you black out the days until the chimps face is obliterated, and then, voila, mission accomplished! This one is great for dorm rooms or office cubicles and it's actually kinda fun to black off a bit of the chimps face every day. 23" x 35" so pretty good sized. There's a coupon code on the site, for $5 off.
http://www.cafepress.com/scarebaby.86498433