Hello Mobile: 25cent almost untimed phone calls to mobiles and fixed phones.
They also offer totally free calls between other hello mobile users, but you will be disconnected after 20mins but you may redial immediately.
Plus if you port your number to them you will get $5 Bonus credit.
Plus $2.50 extra credit on your first and second recharges you must use a credit card to get the bonus credit.
There are some limitations to the service, international roaming is not available, premium numbers are not available for this service and there is a $8 port out fee. Hello Mobile use the Vodafone network.
I have been using this service for a few months and am very happy with it, but they have altered there pricing slightly in that period and would anticipate they will have further alterations to the pricing in the future.
Sim cards for this service can be brought at most Indian and Asian grocery stores, there is a store locater at the site. Make sure you buy the $10 Sim. Recharges can be made online or at places like 7/Eleven, Caltex, Australia Post.