Abu Dhabi's Emirates Palace hotel has an ATM that dispenses gold. You feed in cash, it emits lumps of gold, using an exchange rate updated every 10 minutes.
According to Emirates Palace, the machine has a range of built-in security features, including anti-money-laundering software. We suspect it also comes with some sky-high fees or commissions. But we suppose that anyone who needs to convert cash to gold so quickly that they'll use this, probably isn't worried about that (though we suspect that they may be a little concerned about that anti-money-laundering software).