Haven't been bicycle touring in Australia, and likely never will, but I thought with all these great wilderness dirt-trail pics everyone's been showing this would be a suitable addition to the discussion.

The Mawson Trail in south Australia, 900km long, through the Ikara-Flinders Ranges National Park area, from just north of Adelaide to Blinman. Looks like an amazing area of the countryside, for exploring via a bike. Stunning scenery, ancient fossils, dirt roads/trails galore.

Australia's trail where life began @ BBC.