Anything really can work as money, have you herd of the rainbow gathering? well during this event using any form of paper money is frowned upon and people are encouraged to use the barter system to get anything they may need for the duration. Now of course this sounds good until you realize you need a base currency to sort out odds and ends in transactions so they started using snickers bars as a currency when trading in just goods didn't amount to a fair trade for both parties. Of course this isn't the best example as snickers are a manufactured product that you have to buy but it does show anything can be viewed as money from the right prospective.