How to Promote Liberty
1. Political. Identify and support candidates who agree with your views and will try to implement them.
As I read the current news, Barack Obama is in the process of demonstrating why that approach mostly does not work. There are increasing signs of disappointment from people who supported him in the belief that his policies, both abroad and at home, would be radically different from those of his recent predecessors and are concluding that they will not be.
I suspect they are right. It is quite likely that Obama will expand the size of government, but the reason is not that he is a left-wing ideologue but that he is a practicing politician; the current financial crisis provides excuses to spend lots of money, a situation politicians are almost always glad to take advantage of. Given these circumstances, I expect that McCain would also have substantially expanded the size of government, just as Obama's predecessor did, with a different set of excuses.
2. Intellectual. Promote your ideas in colleges, in newspapers, in any way that will spread them, ideally to people themselves likely to be influential in passing them on.
This is a popular approach and probably does some good. Its limits come from the fact that the crucial resource in spreading ideas is not money but people, in particular smart people who like the ideas and are eager to expand and spread them. One H.L. Mencken or Adam Smith or, on the other side, George Bernard Shaw is worth many millions of dollar spent subsidizing ideological magazines or college lecture series.
This approach also has a danger, what I think of as the rice Christian problem. Rice Christians were Chinese who converted to Christianity because the missionaries had rice. In the political context, the equivalent are people who adopt an ideology because doing so is profitable--gets them a good job, government or private grants, and the like. One disadvantage of being the party in power is that your missionaries have a lot of rice, which increases the number of converts but can badly reduce their average quality. To a much more limited extent, that can happen with private donations as well.
3. Indirect. Find ways of spending your money that will encourage changes in the world whose effects go in the direction you want.
The most successful example that occurs to me, although it does not have a lot to do with libertarianism, is the invention of the birth control pill. My understanding--readers who are better informed on the subject are invited to correct it--is that its development was subsidized by a donor who thought a reliable form of female contraception would have social effects she approved of. I do not know how nearly the effects fitted her intention, but I think it is clear that that particular technological development had very large effects on the society and did so at the cost of a trivial investment.
A more recent libertarian example, on which the results are not yet in, is my son Patri's seasteading project. The idea is to develop an inexpensive technology for floating housing. The theory is, first, that it would make taxpayers more mobile, hence governments more competitive, and second that it would open up opportunities for small scale floating polities ouside the control of existing governments. My guess is that, like most such clever ideas, it won't work--but if it does, it could have very large effects over the next few decades in a direction that I would approve of.
Another possibility, which I do not think anyone is pushing at the moment, is the development of anonymous digital cash. Interested readers can find a discussion of the idea in my recently published Future Imperfect. So far it has not happened, probably because many governments would very much prefer that it not happen. But if it did come into existence, it could considerably reduce the ability of governments to control their citizens, especially in their online activities.
Readers are invited to contribute their own suggestions for how to spend money and talent promoting liberty--or, for that matter, promoting alternative large scale objectives.