Most kids (and kids at heart) are familiar with these coins (sometimes called pressed pennies, squished pennies, smashed pennies, or by the official name - Elongated coins)
Elongating penny machines can be found througout the United States (and other countries) and usually depict designs from a specific location or event. You insert a few quarters and a penny, then two steel wheels come together with more than 1,500 pounds of pressure to flatten the penny and imprint it with the design. Most machines are found at various types of attractions, providing an inexpensive and unique souvenir. Some of the older rare elongateds command high prices, but most still remain one of the least expensive and most unique collectibles available.
The first U.S. elongateds were rolled in 1893 at the Columbian Exposition in Chicago, Illinois. Over the next few decades, entrepreneurs appeared with their dies and rolling machines at many fairs and expositions. In the 1950's, the U.S. Treasury provided assurances that elongated U.S. coins are indeed legal. In the 1980's, a further expansion of the hobby occurred when customer operated electric and manual rolling machines began appearing at amusement parks, museums, zoos, and other attractions. Today these machines are found at thousands of locations worldwide - with more than a dozen in the Shenandoah Valley (in Virginia).
A great organization that promotes and educates people to the elongated coins is a non-profit organization "The Elongated Collector" [TEC] (tecnews.org).