Being Australian, I can only relay what I've heard from foreigners that I've met in Australia. With that proviso, I believe that the working holiday visa that Louie was talking about is valid for a maximum of one year, non-renewable. Staying after the term of the visa would require either (i) getting officially sponsored by an Australian company or (ii) marrying an Australian. Even in those two cases, you're likely to be forced to return to your home country to apply for the new visa.