A nice succinct post on the Australian Legislation with some useful links can be found on Deliverability.com
Excerpt:
Enforcement Effects:
According to the ACMA, as a result of Spam Act 2003, 200 businesses have since been required to amend their email practices, five businesses have been fined over civil penalties totaling $20,000, and three businesses have provided enforceable undertakings. The ACMA has recently begun a federal case under the act against three companies for allegedly sending mobile users unsolicited SMS messages concerning Australian dating sites, seeking fines of up to $1.1 million per day. A hearing has been set for February 6.