The local rules state:

Radio transceivers are required. The only radio transceivers that
may be used in Australia are 477 Mhz Australian UHF band and Airband radios. 2
Meter radios are not legal for aviation use in Australia.

This last two sentences are complete bull shit. I don't know who
is trying to pull a fast one here, but I have been using my 2 meter radios (both
Belinda and I are licensed) in Australia for over a decade. It is quite legal to
use them in the manner than we have used them (me talking to Belinda while I'm
flying and her talking back to me). Previously one needed to have an Australia
ham radio license (both Belinda and I have ours), but that hasn't been true for
years as long as you are licensed in a country that has the normal license
exchange agreement with Australia, like the United States has.

This rule means that you will be required to purchase a UHF radio. I suggest
that there are severe restrictions on who can sell these and aviation band
radios in Australia and are much higher priced there than they would be
otherwise. You might think about picking one up on the internet before you go
there. And, of course, change all your Push-to-Talk gear.

Perhaps another way around ridiculous rule is to purchase a very cheap UHF radio
and carry that along with your operational and perfectly legal 2 meter gear.

These radios cost $90 AUD each. These are much cheaper:
http://www.uniden.com.au/AUSTRALIA/p_uh037sx4_index.asp or
http://www.uniden.com.au/AUSTRALIA/p_uh037sx2_index.asp at thirty dollars
each found
here.