Alternatively, Google has a feature that calculates currency exchange rates. You could use that to convert AUD to USD, and then calculate the Bitcoin value from that:
http://www.google.de/q=55.95+AUD+in+USDI was trying to avoid doing double conversion, as it quickly gets confusing, and I'd have to update prices each time USD/AUD changes, as well as each time USD/BTC changes. Either that or I'd have to build in a buffer amount, which I'm trying to avoid.
Maybe I'll just have to start an AUD exchange!