The Infinite Cat Project is an impressive, and rather silly, collection of photos of cats staring at photos of cats staring at photos of cats, and so on. Currently it's just presented as a collection of photos.
It would be interesting to present it instead as a video showing a continuous zoom out from the first image. As the cat obscures part of the previous image in almost all cases, it'd be necessary to combine, scale and crop several images to produce any frame in the video.
Piet Delport noted that there are now a couple of implementations of this on the Infinite Cat Project movies page.