Learning is itself a social activity, requiring some degree of dialogue.
Some learning networks are suboptimal due to a too strong focus on “best practices”. Of course, best practices can be very educational and they do in general offer valuable content, but if the focus is only on best practices the participants are not invited to learn from average or bad practices, and they may even be discouraged from bringing those up. Thus, the best practices could lead to a kind of politeness, where one does not dare to stray from the content of the best practices. True learning is hampered in such a situation.
Dialogue takes place within ‘containers’: contexts in which the participants feel sufficient trust to speak out honestly and genuinely, while having genuine attention to the others. This container has to be build.
Experience shows that the trust that is build in the ‘container’ of the whole group is not necessarily there when the members of the group have to work together in smaller subgroups or duos. This is not necessarily a problem; it just means that some effort has again to be devoted to building trust.
Trust also has to be maintained, as a kind of hygiene of the group. Learning is confrontational, especially in learning networks where one wants to do something with the learning. One has to entertain new ideas, come to terms with confusing notions and probably make a few mistakes. This one can not do in a group setting without sufficient trust.
Examples of learning networks are abundant, although they are not always called "learning networks".
Networks are far from new. The first publicly listed company, the Dutch East Indies Company, founded in 1602, was in fact a network of networks of traders, united to a common interest. There have been networks before that and there is an increasing number of networks since. These days, there are especially networks amongst the small and medium sized companies. These existing networks have perhaps a good start in developing into learning networks, in that they already have a history around shared interests and a basic level of trust amongst their members (especially the kind of trust which relates to the shared interest). What they do not always have is a culture in which the things they share are seen as learning opportunities, relevant to further development.
There are within quite a few organizations these days communities of practice. They typically are organized around specific issues and unite both experts and new practitioners, typically dispersed over the globe and connected through the internet.
The peer group is another example. The challenge here may well be that there has to be a balance between the trust that exists between peers on the one hand and the challenging and learning that has to take place on the other hand.

It remains improtant to have the motivations of the respective members clear to all and made explicit from time to time. Why would you be in a learning network? It is perfectly ok if you are motivated by the comradery of the network, but if that pushes into the background a motivation that is related to the subject matter and goals of the learning network, you have a problem (one that can be dealt with, by the way.)

Do you perhaps have experiences with the learning dimension of networks in which you are active?