In Australia, we use Australian dollars – not to be confused with US, Hong Kong or any other dollars. XE Currency Converter will help you convert your own currency at the market exchange rates.
Currency exchange is available at banks, hotels and international airports. Cirrus-compatible ATMs are everywhere, banks line most main streets, and credit cards are widely accepted. Keep in mind, there’s an AUD$10,000 limit for bringing cash into the country (if you bring more, you’ll have to declare it at the border).