“Time to dig through my pennies.”
I had the same funny thought, so I did some research. Today, pennies are over 99% zinc, with a very thin copper plating. Prior to 1982, pennies were 95% copper, and there were roughly 145 pennies in a pound. So, if you have a jug full of pennies saved from 28 years ago, you can triple their value by melting them down.
It is against the law to melt-down US coins.