With respect to the seastead societies, which I've heard about, I think it's certainly plausible that they'll "work", given sufficient diversity of available governments, and hence, appropriately homogenous small-scale populations. But in a geopolitlcal landscape ruled by nation-states, I would be truly wary of breaking down powerful liberal democracies like the US into anything resembling these things. It's rather unclear to me how you could mobilize a sufficient defense against nationalist military forces.
I recall reading in my undergrad days about similar small, voluntarily formed communities. (One of them, for instance, eschewed all laws and use of coercion, relying on subtle and not so subtle forms of ostracization to keep people in line.) But it occurred to me that these communities were entirely dependent on having a larger, more powerful neighboring entity around to protect them, and I have to believe these seastead societies are subject to the same dependency.
Here's the FAQ: http://www.seasteading.org/learn-more/faq
Here's the book-length treatment: http://seasteading.org/seastead.org/commented/paper/index.ht...
By the way, Patri's group has raised $500,000 from Peter Thiel to pursue their ideas. If you live in the bay area, you can attend social meetings of the Seasteading Institute, though I'm not sure what goes on there. Patri has very avant garde facial hair.
As the libertarian movement has grown it has become more ideologically diverse and more moderate on average. There are few fire-breathing anarchists around any more (David is not a "fire-breating anarchist". Murray was.).
On the empirical side, he does have a very nice chapter on Iceland, which went without a public bureaucracy for a few centuries. Law enforcement was essentially a private business for awhile. It's a good read.
I know that one of the big Public Choice guys did some writing on the feasibility of anarchy (Buchanan, I think). However, I'm not sure if it's the kind of work you are looking for. There's been few functional anarchies on this planet that we know about, and it's not a topic that gets most economists published. I'll let you know if I find anything.
If you're looking for information on the problems of collective action, then the Public Choice guys are definitely the place to start (Buchanan, Tullock, etc.).
David's son, Patri, runs the anarcho-capitalist Seasteading Institute, which aims to create seastead societies on the ocean (think "Water World", without the suck). He believes that seasteads will be more resistant to government monopoly, since a group of people who did not like their government could simply float to a different one.
Given the results so far, other libertarians encourage the Friedmans to breed as much as possible.