I like film photography and use up a lot of film. I also needed a new key chain as my old one was made out of leather and was falling apart.
Light bulb! I take my film to the local Costco and Lily is on friendly terms with the people behind the counter. So I asked them if they could spare the old used 135 film cartridges.
Boy, could they. I got about a dozen and picked out some different color ones. I got some 1″ key rings from Home Depot, Dad has a drill press in his work room and in a few minutes I had new key chains.