so cell phone calls are transactions. they can be seen itemized and if you are roaming, they involve moving charges between different agencies. the transaction cost overhead are extremely low. Now, look at bank charges. why are bank charges typically two orders of magnitude higher than cell phone charges? there is no reason for this whatsoever - the technologies could actually be the same.
I know that its been reported that people in parts of Africa are using call minutes as a currency and that you can buy potatoes (for example) in some markets in exchange for sim magic tokens
this is not pixie dust - its clear we are being ripped off royally by banks and that its time someone started the first mobile virtual internet bank