Small Scale Solar Cell Applications?

I am considering making a small solar cell product for a project that will produce a small amount of electricity to power some sort of electrical every day device. It will only work for small applicatoins (less that 2 square inches) and it won't produce enough power to power something large (like a toaster).... show more I am considering making a small solar cell product for a project that will produce a small amount of electricity to power some sort of electrical every day device. It will only work for small applicatoins (less that 2 square inches) and it won't produce enough power to power something large (like a toaster). Are there any small scale applications for solar cells that I would be able to make a prototype out of?

(some examples of my thinking include a cell phone charger, keychain, earphones possibly? -things related to the lives of teens/consumer products)

any ideas are welcome, i need some inspiration
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