I recently saw this post on Stumbling & Muttering alleging that there are a lot of similarities between libertarianism and marxism, but that libertarians are deeply in horror of this idea and refuse to acknowledge it.
So, as a basically libertarian kind of guy: I acknowledge it. Libertarianism is essentially a slightly tweaked form of marxism. Both philosophies are extremely materialistic and principally concerned with the ways in which coercion and freedom interact with economic need. They have slightly different views of “human nature” that lead to very different preferences about future policy, but they usually share a view of history and a critique of the many political philosophies that come from a very different fundamental understanding of importance of economic need.