change your passwords

and never use the same password for multiple things again.
Enable SMS security on your online bank account, or better yet get an RSA token. (most of the big 4 offer them for free)
Just keep an eye on your stuff.
The other thing you can do deek to try and avoid identity theft is sign up for mycreditfile.com.au credit alert which is run by Veda who do all the credit checks in Australia
they have a system you can purchase for $50 a year which includes an email alert when your credit file is changed. So if someone applies for a loan in your name and its not you, you should know pretty quickly soon after and you can get it stopped there and then, rather then going through the mess it turns into months later.