David Cobb, Green Party candidate for President last time, could often be heard saying 'Principled Conservatives and Principled Liberals would find more of a home in the Green Party than in either of the mainstream parties.'
He worked and campaigned with the Libertarian candidate - Badnarik - staging their own debates, and they even got arrested together.
The initial lawsuits in Ohio over the recount were a joint issue as well.
The described alliances are just beginning to take shape, the hard part seems to be waking up and activating (using the Air America term) the sheeple.