I just came across these at Repeat Impressions. They call them Flip Stamps and Flip Cards. There are five stamps in each set -- the image changes a bit with four "flips", and on the fourth there is a saying.
All Occasion Flip Stamps
Funny Flip Stamps
There are a couple more pages of Flip Stamps. And I am seriously considering the Flip Card Kits. I've never been able to make a really straight, totally workable waterfall card.