For remote flying for the first time:
Take a camera with a couple of spare data cards.
Water at remote airfields may be unwise to drink, if present at all. Take plenty of bottled water.
Museli bars are good for keeping blood sugar levels up.
Actually, any advice about remote area driving, available from your local RAA, is relevant.
Take spare spark plugs and alternator belt.
NextG phones work at around 10,000 feet, somewhat near towns.
GSM phones quit working at about 3000AGL, regardless of how strong the phone thinks its signal is.
If you're unable to get internet access, you can still file flight plans over the phone, for free, by calling 07 3866 3517
SarTime can be submitted as well as cancelled on 1800 814 931
Dont get lost in the Woomera area.
Take some warm clothes. The desert can get pretty chilly at night, especially if you've had a forced landing. Unlike in the movies, kangaroos will not summon help.
Post some photos on the More Photos thread when you get back