I am currently protesting against the Democrat party until they stop being the Republican party with another name. Until then I refuse to vote for any major party.
My general feeling is that if both our major parties are on the political right, I'll have to make a major party out of one of the minor parties on the left.
So, depending on who's running for what, I vote Labor, Green, or Libertarian. Note: The Libertarian Party is not on the political left either, although many people confuse them for this. If there are no Labors or Greens running for something, I vote for the Libertarian Party merely because they're at least not on the political right! :D