"Our best selling domestic coin, the MicroNickel will completely encapsulate the Micro SD memory card, having capacities of up to 16 gigs. This device is precision manufactured from actual coins, and is indistinguishable from a solid coin to the naked eye! Memory card not included." More from Maker’s Market, from Make>>

(Note: Newest chip is now a 32 Gigabyte microSDHC card the size of a dime, which will hold the 7,000 iTune songs you must keep secret.)