In case you went to a wedding recently (or you are old, sorry), you may know disposable cameras. ~27 pictures on film and a lot of plastic waste.
I wondered if it's possible to make something useful with them instead of throwing them away. The answer is: kind of.

Re/Upcycling disposable cameras for toy lenses:

Video: https://www.youtube.com/watch?v=mnvB71b50wY

Blog post: https://volzo.de/thing/recyclinglenses/