The point just came up in a comment: how do you define "libertarian"? (I am not saying here that I am one, because messing with politics is intellectual suicide, but it may be closer than any other political philosophy I've seen, from what little I know.)
I find that the more you mire it down into specifics, the more muddled does the concept become. To me, it means at its basic: Don't f**k around with my life, and I don't f**k around with yours. Or more positively: I have no interest in controlling what you do, and I'd be happier if you don't attempt to control what I do.
Of course the problem is that we all want freedom to do whatever we like, but when others do something we don't like, that's offensive and should be curtailed by whatever means we have!
I guess it's also connected to the alternative political spectrum: not left to right, but centralized versus decentralized. A totally empowered world government at one end, and a totally empowered individual at the other. I lean towards the latter.
What I would love is for a philosophical discussion of liberty, it's an interesting and important and difficult principle. But sadly this kind of thing usually quickly becomes a political discussion, in the meaning of "strife of interests masquerading as a contest of principles," as Ambrose Bierce said, and seldom were truer words spoken.
An unrelated point: our libertarian friend Kent has an odd characteristic: when he makes a comment on this blog, I don't get the usual e-mail notification about it. I hope this is not true of too many people, because I want to read the comments. Does anybody have any clue as to why this should be so? (I've checked my spam folder, they are not there.)