3 ms·

Your list reminded me of http://en.wikipedia.org/wiki/Rai_stones http://en.wikipedia.org/wiki/Rai_stones

• stephengillie 11y ago
  "While the monetary system of Yap appears to use these giant stones as tokens, in fact it relies on an oral history of ownership. Being too large to move, buying an item with these stones is as easy as saying it no longer belongs to you. As long as the transaction is recorded in the oral history, it will now be owned by the person you passed it on to—no physical movement of the stone is required." That quote reminded me of Bitcoin's block chain.