Oh, well, if we're going to include pinhole...
I've got a pinhole camera I made from the roll core out of a mini-lab print paper roll (don't recall what machine or paper brand). I saw them about to toss it, and asked for it.
It came with a pair of plastic plug caps with reduced holes to center the roll on a spindle, and by coincidence is an exact fit for two 9x12 film sheets (so exact they'll hold each other against the inner surface with the film edges butted together at both seams), short end to short end, wrapped inside the tube.
I blacked out one end cap and plugged the hole, then installed a 1/4-20 blind nut in a piece of 1x2 board for a tripod mount; on the other end cap, I trimmed away some internal bracing and glued a lid from a steel food can on the outside, drilled a centered hole and mounted a pinhole behind that, using a small magnet (wrapped in blue painter's tape for easy grip) as a shutter.
The whole thing is pretty compact, and makes a 9x24 two-piece negative with a 360 degree panorama (angled "upward" if the camera is standing upright on the tripod mount).