Dave...?

If you need to smuggle some data across the border: Hollow Spy Coins.

On the following pages are exact duplicates of Cold War Spy Coins. They are all precision machined from actual coins, and are absolutely indistinguishable from a solid coin to the naked eye. They can be safely handled without danger of separation, and could easily circulate without detection. These exact replicas are proudly made in The USA.

Their newest product is a $30 nickel that holds a Micro SD card -- which can store up to 16GB of data.