Dear Hmmm..,
The FAA does not "validate" any foreign licences anymore. But fear not its not that hard. How it works is thus:
1. Medical
2. Comm exam
3. Flights test wioth FAA Examiner of airman.
Get an FAA Class 1 medical in OZ (lots of Drs here can do it - just ask CASA who your nearest is) b4 you go to save time. (They will issue it on the spot usually). It is a basic medical compared to the CASA, JAA or NZCAA ones.
You then need to sit your CPL theory (1 exam only) - there are excellent CD ROM base courses from ASA or King for around $ 100 AUD on the web. Its easy compared to the CASA, JAA etc.
Next go to the FAA office when you get to the US and they will give you a restricted PPL gratus. Any flight school in the USA will give you a couple of practice / famil flights in a Cessna etc and then you can do the flight test.
If you go there and do it all 2 weeks should do it. But beware at present there are zillions of unemployed US citizen pilots with experience and local knowledge. Try Florida perhaps, I know of a few Ozzies & Kiwis who have gone to big schools there (ie Comair etc) and done the CPL, CFI & IR tickets and scored a job on the student / ltd work Visa programme. They have all progressed onto regionals now and got their Green cards while instructing (takes some time and $$ though).
Good luck......
