From Disney:
"Also called elongated coins, pressed pennies are created when a coin is squeezed between two rollers, one of which has an engraving on its surface. As the penny is flattened into an oval shape, the engraving roller permanantly presses a special picture or message on it. Penny-pressing machines here feature Disney characters, theme parks lands and attractions, and special events."
It's an inexpensive souvineer, it costs $ .51. The machines are everywhere at WDW and they sell a little book that you can keep the pennies in. If you go to guest relations at the parks, they will give you a list of all the pressed penny machine locations.
I've never stayed at CS, but my list says there is both a penny and quarter machine at the Jumping Bean arcade. The penny press designs are the Princess Series #2 of 6 Cinderella, Cinderella 2 or 5 and Seven Dwarf Series #1 of 8 Dopey. The presses quarter is Carpenter Mickey 2 of 5. They designs come in a series. -Stephanie