Ryan Howerter, a graphics design student at Colorado State University has made a functioning pinhole camera out of a 2x2 Lego brick. This hollowed out brick and a bunch of trial and error produced the tiny photographic art that you see here.
Howerter comments on the camera:
The most challenging part is definitely trying to get an actual photo out of it. It's far too easy to over or underexpose the paper or film. I think it was about a 10-second exposure for the one held by the minifig.
The brick's central support tube needs to be removed, which probably requires a Dremel tool. A black brick works best, to minimize reflected light
The material list is fairly small for this tiny camera, I suggest trying for yourself. Utilize a black 2x2 Lego brick, hollow it out, a small piece of brass shim stock which is what the hole is poked through, some black tape to seal the bottom, some photographic paper and of course all the chemicals equipment used for developing photos. Just watch this video and reduce it to small brick size.