In Reply to: Agreement posted by Mic on Thursday, 12. February 2009 at 07:52 Bali Time:
Age is 18-30.
"The Work and Holiday visa is for tertiary educated* people aged 18 to 30 who want to travel and work for up to 12 months in Australia."
http://www.immi.gov.au/visitors/working-holiday/462/
Current requirements for those that can apply:
http://www.immi.gov.au/visitors/working-holiday/462/eligibility.htm
"Note: Australia has agreed to a Work and Holiday arrangement with Indonesia. The signing and implementation of the arrangement is expected to take place later this year. It is not possible for people from Indonesia to apply for this visa at present. Information about the commencement of this arrangement will be published on the website when it is finalised"
http://www.immi.gov.au/visitors/working-holiday/462/