Okay, I buy this thread as an interesting "thought exercise." Though I would point out that in every historical hyper-inflation event I've read about, people still did most of their trading in cash. Yeah, the cash might not have been worth much, and you in fact may have needed a wheelbarrow to take it to the market (this has happened), but it was still a major moving force in whatever economy there was.

My guess? It's still more efficient than any barter system. It's just too hard for small buyers and sellers, each having what the other wants, to find each other. A roadside stand selling lemonade, bullets and beans on a barter system is a waste of time. (My $0.02, though I think it's true.)

Blast is right on the money. And what is he selling? A service, not a good. Like others who suggested it, services are the key (a service being a person with expertise, tools and materials to solve your particular problem).

Proof, you say? I saw news reports after the Haitian earthquake of guys recharging cell phones with bicycle-powered chargers. Seems the towers were operational but few people had off-grid means to charge their cell phones; and in the third world, everybody uses and needs their cell phones. Instant business -- cash on the barrel head, please.