Government are such a bunch of criminals. If you and I agree to swap tomatoes for eggs then we have agreed upon a private currency. (I remember years ago listen to the tax thief in chief saying that if someone did swap tomatoes for eggs with their neighbour then they 'had' to report the value difference for tax purposes. Bloody thieves)
Anyway, here's a mob looking to start up a private currency, I don't know much about them though DYOR.