One of the most visceral ways I experience networks these days (more so than in my consulting practice or academic studies) is through my ongoing job hunt. Networking is a critical skill for job seekers. Something like three quarters of new hires come about because of a personal connection. Often the position filled is never advertised at all, but is created on the spot when the right two people connect.
I have learned tons about the nitty-gritty of job-hunting and networking through a group called WIND, which stands for "Wednesday is Networking Day." For a nominal fee, you can attend any of several weekly meetings (including days other than Wednesday) and boost your own networking through "guerilla group" discussions and "needs and leads" announcements. Each meeting ends with an hour presentation by a professional in the field of career development, often on some topic closely related to networking.
Most helpful of all the resources I've found through WIND is the "buddy group." Job hunting is tough and it helps to meet with a regular small group of people who are in the same boat. With most of my everyday friends, the "how's the job search" question started getting awkward a while ago, for one reason or another. When we ask or answer that question in the buddy group, we really mean it, both in the spirit of support and of accountability.
One utterly fascinating subject I've unintentionally explored in job-hunting networking groups is the dynamic of eight (or so) mutual strangers sitting down for an hour of unfacilitated group discussion on a vaguely agreed upon topic. Perhaps I'll devote a future post to this. Suffice to say for now that these kinds of group discussions don't usually turn out pretty, except in their re-telling as humorous anecdotes.
On a more academic note, Mark Granovetter's "The Strength of Weak Ties" is the indispensable social networking classic of job hunting. His point (first made in 1973) is that my close friends know many of the same people I do and so can't help my job search very much; but my acquaintances know mostly different people than I do and so can introduce me to opportunities I would never otherwise hear about.
See also today's Wall Street Journal for an article on online networking as a powerful job-hunters tool (note: you need a subscription to read it). It includes tips on using services like LinkedIn: (1) Don't delay, these services won't be free much longer, (2) Network with friends first, (3) Get to the point, (4) Quality before quantity, (5) Do your research, (6) It is more blessed to give than receive, (7) Reach out and work the room, (8) Be patient, networking takes months, and (9) Get references from others to get your online profile noticed.