Put little images on springs and place them amongst the books on the shelves -- better still, have someone else do it. The springs are compressed by the book, so when you take it out, voila! A pop-up (or -out)!

Come to think of it, this is a way libraries could supplement their budgets - by selling advertising space on pop-outs. The advertising could even be market oriented: restaurants and food stores in among the cookbooks (DDC 641.5), antique stores in the 700s, then there's the untapped market in 612.6....