While building stronger social networks has lots of benefit to you (helping you get jobs, be healthier and happier, able to mobilize others for entrepreneurial or political efforts, etc.), we’re much more interested in social capital because of the public benefits to those networks. In other words, if people have much stronger social networks, public benefits flow, even to those who are socially isolated, like more responsive government, less crime, better public health, less corruption, more trustworthy behavior of strangers, more well-working schools, etc.
Nonetheless, SocialMediaTrader has an interesting post on how to build one’s social capital and talks about how Paul Revere and Quincy Jones were extraordinary social capital builders. [SocialMediaTrader relates the story we’ve told before that it isn’t a mystery why Paul Revere is well-known as the person who alerted colonists that the “British Are Coming!” whereas another rider William Dawes who also rode out to towns to alert colonists that same night is not. The difference was that Paul Revere knew the “social hubs” in these towns and thus the people he told, in turn told many others, so many more learned of the British plans from Revere than Dawes. Dawes often told more socially marginalized townspeople who only told a few and word spread less quickly.]
Another very interesting article from some years back about someone with an amazingly diverse set of networks is “The Six Degrees of Lois Weisberg” (by Malcolm Gladwell)
Also Bill Sherman has a number of blog posts related to how to build social capital.