Okay Alikim, I have been looking into this problem myself, and I think it sort of boils down to this:
1. You need to get your Bitcoins into your Mt.Gox account
2. Sell them for AUD
3. Do an international bank transfer into your Australian bank account from Mt.Gox
This involves your international bank swift number, you should be able to find that on your bank website
Problem with this is, westpac takes $5 for all incoming international bank transfers, no matter what bank your with, so by the time you get your money, depending on your bank, and banks in-between it may cost you $30, or more =/
Or you could go with a site like spend bitcoins,
They will pay you current price for btc.
Or you could find someone local that wants them
Or find someone on the forum that you can trust.
I am trying to find a way of getting btc for cash in Aus, but there is this problem of trust =/