I've had several people ask me recently, "What exactly is libertarianism, anyway?" I've attempted to answer these rather succinctly, as these folks weren't looking for a dissertation, with the phrase, "We should be allowed to do whatever we want so long as we don't interfere with the rights of others." I wasn't really satisfied with that answer and so I've plunged into the Wikipedia entry on Libertarianism. What I've come up with are a couple of quotes from that page that I believe to hit the high points of the libertarian philosophy (at least as I see it):
"...individual liberty, constitutionally limited government, peace, and reliance on the institutions of civil society and the free market for social order and economic prosperity..."
"Libertarians are committed to the belief that individuals, and not states or groups of any other kind, are both ontologically and normatively primary; that individuals have rights against certain kinds of forcible interference on the part of others; that liberty, understood as non-interference, is the only thing that can be legitimately demanded of others as a matter of legal or political right; that robust property rights and the economic liberty that follows from their consistent recognition are of central importance in respecting individual liberty; that social order is not at odds with but develops out of individual liberty; that the only proper use of coercion is defensive or to rectify an error; that governments are bound by essentially the same moral principles as individuals; and that most existing and historical governments have acted improperly insofar as they have utilized coercion for plunder, aggression, redistribution, and other purposes beyond the protection of individual liberty."