The Impossible Project makes new film for a range of Polaroid cameras, and their newest iteration is their best yet. With some changes to the opacifier used the film can stand to be exposed to some light while its developing. A side-effect of this is that the you can make a neat little timelapse with a scanner set to auto scan as fast as it can.

Take a look:

I think its a pretty nice gif, but gif files can get kind of big quickly, so here are some links to a few youtube examples, which are a bit slower: The Plant, Some Clouds, Venetian Blinds.

For some reason, my favorite is the venetian blinds:

The fun in all of this for me is the conversion of not only an analogue process, but a chemical process into a digital one. The resulting videos are just slow enough to lose track of what exactly is shifting in between each individual frame. In the case of images which were over-exposed, the development process gradually gains then loses detail before developing to completion.

On a practical note, if you would like to try this at home the specific way I accomplished this was using the linux command line tool scanimage.