Since I had to do some research on this topic recently, here are the results that I have found. These plans are interesting for people that do not call out a lot, but rather use the phone to be accessible.
GoMobile – Pay as you go plans
Southern Cross Telecom – Pay as you go plans
AAPT – GO15 plan (**needs to be bundled with Landline phone)
** – some conditions apply to qualify for $0 minimum spend)
Please drop me a comment if you are aware of others or I have missed something (which I am sure will be the case).