The storage mechanism could be coins.
Unfortunately, coins have been out of circulation for many years.
Coins have an intrinsic value (as in gold or silver).
Tokens represent a value, but have no actual value.
If the world's governments began issuing coins instead of tokens, we could once again carry some value around in our pockets, instead of just 'promissory notes', which are basically IOU's from the government.
That's funny, I just logged on having thought about this and was about to say that this discussion was not directly to the point of 'shouldpermacultureprofit'. Anyway, since we're here I don't disagree that silver / gold are sounder mechanisms in as much are a claim to a single piece of pie rather than a claim which others also hold ad infinitum as in credit / debit. Nonetheless my point was (as Graeber spells out so well in 'Debt') that credit between individuals in relationships is the ideal and oldest model (you say "nice shoes", I say "take them" in the knowledge that if I need something of equivalent value later which you have I can simply go over to your house and say "nice [blank]").
I will leave it at that as I don't want to incur the wrath of Pau by getting bogged down in the 'is gold money' debate.
Acetylsalicylic acid is aspirin. This could be handy too: