An electricity hobbyist has built a machine that uses a 22,000-volt capacitor to cause the molecules in a quarter to "rearrange and nuzzle closer, shrinking the coin's circumference to that of a dime," albeit with an "ear-shattering crack."
Update: Romana sez, "The quote, 'cause the molecules in a quarter to "rearrange and nuzzle closer, shrinking the coin's circumference to that of a dime,"' seems to imply that the molecules aren't already about as close as they can get. In fact since these are metallic coins, the 'molecules' are actually atoms." (see pic)
"Even better, they have a whole theory section, which confirmed that I'd first seen this in th Smithsonian crushing a can in the early 70s." Link 1, Link 2
