So I earn my money in US dollars but I have bank accounts in Australia, UK and US.... what's the best way to hedge against US dollar falling?

- Put as much of your income earning assets into other currencies

- consider a leveraged loan (short USD/long xxx) - citibank and many other banks will do such loans for retail customers.

- buy an ETF such as a CurrencyShares Trust on margin

But if he getting paid in US dollars, won't the exchange rate kill him when he buys other currencies anyway? Seems to me you are only directly impacted by the falling dollar when you try to exchange them.

Most companies [that I know of] with expats pay a cost of living allowance in the local currency so the employee does not have to exchange their dollars to live in the country.

Its already too late.