Steve Smith - its better than to try squeze the image in to narrow place but to keep the 120 flat is harder than 35mm , i guess. And bigger machine is more expensive to send in international post , and it makes very big package to protect it from impact.
Darkroom Experimenter - Do you know 35mm anamorph pinhole cameras ?
May be you can do the same with a lens .
EURAKA , I found how you can make a very big may be 24 x 90 mm negative for 50 people.
You can buy movie film and load it to your cameras stool.
There is a new thread at color film apug forum and they talk about fresh kodak film 0.15 $ per foot.
Or you can design a 35 mm anamorphic pinhole camera as seen at f 295 and publish its plan and send everyone a movie film stool.
Its better than send everyone a film and camera.
Or if you aim to philantrophy , you can roll a very big paper and every country , every city stamp it and send each other and finally to you.
When we return to film posting to people , they put developing fee plus film fee in to the mail and send to you.