Wired is running a story on how social networking technologies support, rather than diminish real-life networks of people:
Technology makes it more fun and more profitable to live and work close to the people who matter most to your life and work. Harvard economist Ed Glaeser, an expert on city economies, argues that communications technology and face-to-face interactions are complements like salt and pepper, rather than substitutes like butter and margarine. Paradoxically, your cell phone, email, and Facebook networks are making it more attractive to meet people in the flesh. [...]
In big cities, our communication tools are especially helpful because they keep us from getting lost in the crowd (which is not something you worry about in a one-street town). There are even services that tell you where your friends are by locating their cell signals.
New technologies can strengthen ties within your business, too. A 2007 study by economists Neil Gandal, Charles King, and Marshall Van Alstyne looked at the networks formed by 125,000 email messages from the staff of an executive-recruiting firm. It found that email's real value isn't in communicating with Kuala Lumpur but with Betsy in the next cubicle. The most productive workers have the densest intracompany email web.
This is nothing terribly new; it's reaffirmation of Jane Jacob's view of economies of agglomeration in cities; as well as more recent studies showing essentially the same things; the "weak links" of email and other online communication bolster local interaction.