Your passport has many uses beyond getting you in and out of a country. It can serve as a travelogue of sorts, showing you where you’ve been and taking you back in time as you relive trips stamp by stamp. It can also be a form of identification, or a way to remember what you looked like five years earlier, when you had that flattering (or not so flattering) photo taken.
Now, if you live in Finland, it can also be entertainment. Their new passport works like a flip-book. Each page has a photo of a moose, which walks forward when the page is flipped. Cool idea, no?