Have you read Nick Szabo's Shelling Out: The Origins of Money

I think you'd really enjoy it. It's about the history of money, how it distinguishes humans from other animals, and what people have used in earlier times for money.

What are people bartering with in Cuba? That "double coincidence of wants", that is the main problem with barter, has got to make it tough. Is there any one product that is taking the place of money?

I know in some early pioneer communities in the US, in the 1800's and earlier, before coins were widespread, certain commodities became a standard for money. For instance, sorghum syrup, by the quart, was a type of money in some areas.