What is the easiest way to get out of the USD?

I want to convert some of my money (American dollar) to the Austrailian dollar. The goal is to keep it in a savings account after it is converted, and not touch it for a few years. I just want to diversify in case the USD goes down. Now what is the easiest/best way to go about this. I looked at Forex accounts, but they dont give any mention of this strategy. They just push trading. I wouldnt mind going to a bank, but I know nothing about if they would allow me to keep a foreign currency in a savings account. Not sure what I should do. Thanks for any help.