voip =calls to AUS landlines are free and mobile 6p a minute. have fun.
voipraider http://www.voipraider.com/en/index.html
Is this on PAYG or only on pay monthly?If the person you are calling is with Vodafone then get them to call you as there is a promo running until the end of the year where they can call you on a landline for up to 1 hour and it only costs NZ$2. I call the UK pretty often and it's a great deal (better than 2 degrees unless you only talk for 2-3 minutes).