Australia has an excellent anti-spam law, the Spam Act 2003.
The Minister for Communications, Information Technology and the Arts, Senator Helen Coonan has called for public submissions as part of a review of the Spam Act 2003, to be completed by April 2006. "The Australian Spam Act is internationally recognized as a leading legislative model to crack down on the scourge of spam that is overloading people's in-boxes and causing great frustration," Senator Coonan said. "Since the Act came into effect, many professional spammers that had been based in Australia have either shut up shop or left the country."
Australia's Spam Act applies to commercial electronic messages which include spam sent via email, SMS, Instant Messaging and Multimedia Messaging Service.
For more info, see http://www.dcita.gov.au/ie/spam_home/spam_act_review.