We have quite a number, but we run a two party system, so the party in power is either Liberals or Labour. The next biggest is probably the Greens, followed by the Nationals, then you have all the small "niche" parties - Australian Christian Lobby, Family First, Australian Sex Party, and so on, you can tell by their names what they stand for and they tend to not have a "whole country" view, but strong views on one or two key issues.
Here is a good list of them: http://en.wikipedia.org/wiki/List_of...urrent_parties
If enough Australians got sick of the two major parties, there is usually enough Greens candidates that they could actually win a majority and take power, but enough devious pollies have put out the word that a vote for Green is a vote for Labour, and so a lot of people feel voting Greens is a wasted vote. Aside from that, no other party really has enough clout to actually take power really, and none have the support.