America has trouble with a simple problem: sending money from person A to B. You can write checks, but they take days to mail, and more days to clear. There are credit cards, but they charge huge fees and are intended only for merchants. There’s PayPal, if you don’t mind more fees and money being frozen for six months on a whim.
A simple solution:
– Withdraw cash from your account.
– Walk over to the other person’s bank.
– Deposit the cash into their account.
It’s perfectly legal to deposit into someone else’s account. You don’t need their ID or credit card, just their bank’s name and account number. And it’s instant. Sneakernets are great.
The Rationalist Conspiracy 
I suppose this works if the other person’s bank has a branch that’s nearby; I wonder about security risks, though. (How do direct debits work, anyway?)
This problem only exists in the United States and Canada — Europe makes widespread use of giro transfers, which are not possible here.
Wire transfer fees are too high in the United States, and there really is no functioning giro model.
Implement giro!
I implemented this solution awhile back, after the bizarre realization that there was no simple way to do this online that didn’t have at least one drawback.
IIRC Paypal only charges fees to businesses, not individuals.
Bitcoin is getting closer and closer to “it just works”. Other person sends you their address as a qr picture, your phone scans it, you send money. No walking involved.