A guy named Peter Suderman has an interesting post up at the Reason magazine site....
Tyler Cowen reads Tom Palmer's new book on libertarianism and identifies five primary strands:
1. Cato-influenced (for lack of a better word). There is an orthodox reading of what "being libertarian" means, defined by the troika of free markets, non-interventionism, and civil liberties. It is based on individual rights but does not insist on anarchism. A ruling principle is that libertarians should not endorse state interventions. I read Palmer's book as belonging to this tradition, broadly speaking.
2. Rothbardian anarchism. Free-market protection agencies will replace government-as-we-know-it. War is evil and the problems of anarchy pale in comparison. David Friedman offered a more utilitarian-sounding version of this approach, shorn of Misesian influence.
3. Mises Institute nationalism. Gold standard, a priori reasoning, monetary apocalypse, and suspicious of immigration because maybe private landowners would not have let those people into their living rooms.
4. Jeff Friedman and Critical Review: Everything is up for grabs, let's be consequentialists and focus on the welfare state because that's where the action is. Marx is dead. The case for some version of libertarianism ultimately rests upon voter ignorance and, dare I say it, voter irrationality.
5. "Hayek libertarianism." All or most of the great libertarian thinkers are ultimately compatible with each other and we have a big tent of all sorts of classical liberal ideas. Hayek and Friedman are the chosen "public faces" of this approach. "There's a classical liberal tradition and classical liberal values and we can be fuzzy on a lot of other things."
These people at Zeal For Truth have added a few more:
Left-libertarian - sceptical of capitalism and corporatism, and possibly even private property.
6. Ron Paul bots - these guys are “libertarians” in that in their support of Ron Paul - probably because he was against the war - has blossomed into a general hate of the federal reserve. These are big on the constitution and “patriotism” and can be seen yelling at rallies or harrasing border guards.
7. Fake libertarians - Guys like Larry Elder and Ronald Regan. Anyone who calls themself a “republitarian.” Conservatives who happen to be a little more “free market” than your standard compassionate religious nut.
8. Libertarians who don’t know it or won’t admit it - People from the left and right who don’t to be associated with libertarians because of one of these groups, but hold a lot of libertarian beliefs.
9. Objectivists - Generally pro-war, radically atheist. Argues for “objective” standards of value (rather than subjective as in the Austrian school). Big on selfishness and a sceptical of utilitarianism.
10. Penn and Teller libertarians - Slightly left-ish, cynical and embracing libertarianism at least, in part, for it’s hedonistic/rebellious appeal. This is who conservatives think of when they realise we don’t like the war on drugs.
I like to think that I'm from the Hayek/Friedman wing. Am looking forward to seeing how TLG, Browncoat and others define themselves.