If battery technology ever becomes advanced enough, batteries could function as money, perhaps even better than the traditional metals did. I am talking pretty far in the future here. One would have to be able to tell how much power was in the batteries and capacity levels would have to be far higher while battery size would either have to stay the same or get smaller.
Now someone with a better grasp of the possibilities of putting large amounts of power into very small spaces may come along and tell me we could never get enough for the idea to work. That's okay, but this line of thought has me thinking- it is obvious that government paper money is bad, but they seem unwilling to allow us to return to the traditional metals. What happens if there is an invented solution?
Obviously the government would use force to keep it's monopoly, but there is a chance they would only recognize the new invention as a battery (or whatever else it might be) and not implement controls until it was too late. Too late, in these sorts of cases is when government people are all using the new money too because it's just that much more useful than the junk that they put out.
I suspect that government forces would then want to secure a monopoly on producing the new invention, but that would open a whole bunch of problems they currently don't have to deal with in the paper money world. The production process itself would be much more complicated than printing money. Governments do not innovate well either. Also, part of their love for paper money comes from being able to quickly inflate the money supply in order to pay for their obsession of the day, whether it be war, or brightly colored straws for schoolchildren to drink their milk with. Having to actually make a real product, one that works in a predictable and reliable way, makes inflation much more unlikely.