Many people remember, some people even have, coins made of silver. Quarters, dimes, even nickels at one point, were all made of silver. Well before silver went through the roof, the US government stopped making silver coins. The coins were left in circulation and, eventually, those who hoarded them sold them for a tremendous profit. In 1982, pennies were switched from being made out of copper to being made out of zinc. Recently, copper hit $3.80 per pound. Because one pre 1982 copper penny weighs 3.11 grams, one pound of copper pennies costs $1.46 at the bank. That means copper pennies are really worth over 250% of their face value, seeing as copper is worth about 4 dollars a pound right now.
Think about this. Copper scrap can be sold for $3.00 per pound at my nearest scrap yard. That means if you simply collected 20 pounds of copper pennies, it would cost you $30, but they coud be sold for $60. If you were selling directly to a refinery, you would get damn near $80.
Now before you go penny crazy, you should be told that melting pennies is illegal. Most people, myself included, believe that this ban will be melted soon enough, as the price of copper continues to go up.