Sign up at SMSFun.com.au or use my referral link
http://www.smsfun.com.au/ref/1492290
and port your exisiting Telstra, 3 or Vodafone mobile phone/mobile broadband service to Optus (either prepaid or postpaid) , you will be rewarded with 1000 joobz (virtual credit)for ordering gift from the site, include $20 Wish gift cards (220 joobz) ,$50 Wish gift cards (550 joobz),$50 David Jones Gift Card (550joobz) and many others
The site only detects successfully port from other carrier to optus after 1-2 business days.
It usually takes around 10-14 days for the 1000 joobz to credit to your account.
The site also allows you to send Free SMS online instantly.
Term and conditions
http://www.smsfun.com.au/switch-terms.php
You might sometimes see the site says 600 joobz reward when you switch to optus, which is not true, the 1000 joobz offer has been extended til 30/4/2012.
Mod: Removed referral link
SMSFun: Switch to Optus and get horrible reception.
(Yes, I am an Optus customer)