I've found countless uses for those little plastic cans, including protection for respooled film or factory loaded film bought in quantity. In the darkroom they serve to develop test frames of film. They can be cut down to adapt pinholes to many of the shutters found on LF cameras. They can organize and store tiny parts. Kittens and kids may like to play with them. Campers use them to protect matches, food items, and pills. And so it goes.