Polarizing filters can be an essential part of a photography tool set, as they suppress glare, make blue skies pop, and offer an additional way to control the light in your scene. And if you have some old electronics that you can mine for spare parts, you might already have a filter.
It turns out the glass screens on old liquid crystal displays that you can find on something like a calculator or an old Nokia phone have a transparent layer that acts as a polarizing filter. If you disassemble the device (and are careful not to break the screen, of course), you can use it as a rough but ready polarizing filter.
