Paul Beard's made up a cool cigar box pinhole camera.

A brief overview of the cigar box pinhole camera I built yesterday and today.

Built around a 4x5 film holder. Focal length of about 30mm, pinhole of indeterminate size, f/stop 100-150, I think. So reasonably fast -- 1-2 second exposures in Sunny 16 conditions.

Lessons from Mk I that I tried to incorporate:
* use a smaller box so you can more easily remove the dark slides without muffing the shot
* tripod sockets are a good thing
* a shutter is also a good thing: using the dark slide a shutter not always effective. - Link