The "taxpayer" payment is, essentially, for anyone who paid net income tax in 2007/08 and has a taxable income under $100,000. Under $70,000 and you get the full $900. It reduces in steps up to $100,000.
The payment will be made as per any previous tax return - into a bank account if you have provided it, else by cheque in the mail.
Here you go:-
http://www.ato.gov.au/corporate/cont....htm&page=1&H1