Liz Lawley and Brad DeLong run across Mark Granovetter’s classic 1973 article, “The Strength of Weak Ties”. It’s well worth reading. If you’re interested, you can check out the syllabus for the Economic Sociology seminar I taught last Fall. (Update: Whoops, the link goes to the right syllabus now.)
Liz seems mainly interested in using the article to get into the literature on social networks rather than economic sociology. Social networks have become quite the thing recently, with which the publication of a number of popular books on the subect. Some of them are written by physicists and other natural scientists who have suddenly discovered the notion of scale-free networks and its applicability to social interaction. In sociology, the most prominent young researcher in the field is Duncan Watts, who recently published Six Degrees, a pop account of recent work in the field.
Bear in mind, though, that this is a research program that’s been developing in sociology since the early 1970s, and that some of the popular accounts are shockingly unaware of this (particularly the ones written by the physics people). The least-informed ones begin with Stanley Milgram’s notion of the small-world problem in the late ’60s, skip lightly over the intervening period (perhaps mentioning Granovetter’s “Weak Ties” piece and maybe the pathbreaking work of his advisor, Harrison White) and then scoot straight to about 20 minutes ago.
I’m not an expert on networks, but several of my colleagues most certainly are. If you’re serious about getting into the literature on social networks, then take a look first at Forse and Degenne’s Introducing Social Networks, and then Wasserman and Faust’s Social Network Analysis: Methods and Applications. Or just look at Ron Breiger’s Soc 526 Syllabus or (even better) his suggested reading list to get a sense of how rich this field is.