Google Maps' turn-by-turn directions feature for Android hasn't made it to Australia yet. If you're keen for a free turn-by-turn application for your Android, the Brut Google Maps mod might fit the bill.
Commenter Chris suggested Brut Google Maps in a comment on our original post about the lack of official turn-by-turn so far in Australia. The modification takes the existing Google text directions (which, of course, sometimes need to be taken with a pinch of salt) and converts them into a turn-by-turn format. It also adds map caching, which could be very handy in more remote areas.
I did my level best to put the Brut mod to a proper test, but it flat out refused to install on the HTC Legend I had handy (though forum comments suggest other people have successfully done so on that device and others available here). If you have tried it out in Australia, let us know how well it works in the comments.