Karl Denninger argues that the failed stimulus will lead to accelerating deflation in the US. His prediction is that demand for the dollar will soar and other currencies will collapse instead. He thinks this will hit US exports and the economy will be crippled, so Americans need to hold in-the-hand folding money - lots of it, maybe a year or two's basic expenses! - away from the bank.
He may be on the wrong medication - the current state of the world's finances is a great impetus towards paranoia and depression; but if he's even half right, we need to start making those quiet, regular cashpoint withdrawals and (for non-Americans) visiting the bureau de change. And not living in the city.