Does anyone have a super-simple design, something like a film holder, which would allow me to have multiple shots with an odd-sized ultra large format pinhole camera? I've been thinking about a 10" x 16" sized camera, taking half sheets of 16x20 paper: it's 1:1.6 aspect ratio is very close to the Golden Mean or Golden Ratio (as is 12x20,) and I'm rather curious about that right now. But I'd like to be able to make more than one paper negative before retreating to a darkroom (and I don't have a changing bag or tent anywhere near large enough for this beast.)

The difficulty is, mommy wouldn't let me play with tools after the insurance company threatened to cancel her policy and, in all honesty, I couldn't drive a nail if it had power steering. I'm looking for something that could be built with common hand tools. I figure that a pinhole camera isn't all that picky about where the film plane lies; it's pretty much everywhere inside the camera, so the degree of precision of a cut film holder isn't necessary.

Any ideas?