Usually a penny isn't even worth 1 cent but if you have a special old penny it can be worth Millions, $1.38 million to be exact.
A one cent penny fetched that amount of money at a Florida coin collectors convention over the weekend.

The US minted it's own currency in 1793 in Philadelphia and this coin survived. Making it 218 years old. However, the coin was never in circulation. It was said to be in the possession of collector of collector's, Louis E. Eliasberg. He reportedly owns at least one of each coin ever minted in the US.

Ben Franklin is rumored to have designed this particular coin although it's not known for sure to be true. The coin has a chain design on one side giving it it's name "Chain Coin".

More information on the coin can be found at Heritage Auctions, the auction house that handled the sale.