First off, thanks to everyone who voted and/or commented on What Limits the Growth of Open Source ! Minds really brings some great minds and voices to its platform.
In the midst of the discussion, I realized that in addition to growing open source in the sense of open source software, I also see -- and am currently capitalizing on IRL -- an opportunity to take the open source concept beyond the computer.
We most often associate the term "open source" with software, but the general principle is for a group of collaborators to freely share ideas, such that everyone benefits from the new ideas. As the saying goes: "You trade your item for mine and we each have one item. You trade me your idea and we each have two ideas."
The main contrast to an open-source community of real-life information is the traditional model of education. In this case, a teacher or a university had a tight control over access to education and expertise on a topic. Or, a company has a patent or other license. You in turn must pay for access to this proprietary information. By "open sourcing" knowledge in the trades, in science and so on, we can bypass the patent system, and open up more opportunities to effectively build businesses and business models that will offer real alternatives in the trades, medicine, education, science, and more.
Concerning the question of "how to do it," I do see a need for creating a course on either 1) developing a repository of information for a group of people to share, or for 2) developing the kind of systematic communication that is needed to enable the sharing of expertise.
One confusion that can easily be made here, is to confuse "Open Source IRL" with voluntary socialism, which is the idea of sharing things in common. While there are cases where people can directly share goods in a cooperative, this isn't "open source" per se, as me giving you one book, for example, leads to you having one more book, but not both of us. It is not that this is a bad thing (after all, the books on my bookshelf could be influencing people instead of waiting for a re-read), just not under the definition of an open source project.
This leads us to one interesting hybrid case, however. If you had a book scanner or printer, and we collaborated such that I found a rare book, and you reprinted it for me, we could then both have a book, and be able to reprint the rare book as needed. In this case, we are sharing expertise and content, which would fall under an open source project.
I have been active in one Makerspace, and something quite interesting about the Maker Movement is the active sharing of guides on building all sorts of devices, including the development of new tools that other Makers need for common projects. This sharing is loosely organized between "official" channels like Make Magazine, and single-project websites like DIY Book Scanner.
Makerspaces are also a good example of how to develop shared expertise. Spaces are typically owned/rented by a membership organization, which also purchases common tools to be used by members. By having everyone in one space, and having the tools available, members will tend to ask each other for help, which increases everyone's competency over time. This would be one method of encouraging "open source expertise" by fostering communication.
Websites like Instructables allow users to create and share tutorials for a wide variety of projects, and would be an example of a "repository" approach to open sourcing expertise. Here, people can establish a reputation or expertise by sharing knowledge.
One might also say that Minds itself can become a means of open sourcing expertise and practical knowledge. Since users can be paid when others interact with their content, and the way to get interaction is to write good content, I do think that the tendency over time (and with the growth of the platform) will be a growth in shared expertise. Perhaps one day we will see some education-based groups with enough content that independently-schooled students, or just folks looking to learn something new, will be able to find everything they need here, or via projects that are promoted here.