Sim Recommendations for travel to Australia

[Big Apple]

I currently live in the US but will be going to Australia soon for a month and was wondering if anyone had any recommendations for a sim card to use. I do have an AT&T locked iphone which I will be using on wifi where possible for data/email/facetime etc but also have an unlocked dummy phone on an extra line which I was hoping to be able to use for those times I really need to make some local calls and texts. Is it better to order something online from here in advance or get something locally once I get there? Thanks!

 

[miles01110]

Just buy a SIM card at the airport.

 

[dontwalkhand]

When I went to Australia, I used an Optus SIM card in my unlocked 3GS. You can go to a "Yes Optus" store to pick up a prepaid SIM.

 

[Big Apple]

I will definitely wait until I get there then. Thank you very much!