Money is just a medium of exchange, an improvement on barter as a way to buy and sell stuff. But apart from the government, who says that medium of exchange has to be the official currency? Why not bottles of say, detergent?
And if bottles of detergent became 'money,' what might you expect to happen?:
Theft of Tide detergent has become so rampant that authorities from New York to Oregon are keeping tabs on the soap spree, and some cities are setting up special task forces to stop it. And retailers like CVS are taking special security precautions to lock down the liquid.(via)
P.S. Check out the bottom of the article for awesome mugshot of a TIDE FIEND.
P.P.S. Some say the story ain't true, the jury is still out.