On a quick look at travelocity they are only showing Qantas, but I'm sure there are several other budget carriers. Distances in OZ are rather astounding though. Sydney/Cairns is 3 hrs.
"Regional Express" flies Sydney/Melbourne, but only with a change of planes. Qantas flies non-stop.
Here's a list of the regional budget carriers. How many of them fly within Australia you would have to find out.
www.attitudetravel.com/lowcostairlines/oceania/
