Some critics have quickly tired of flash-mobs that began this summer, writing off the phenomenon as “a slightly annoying fad, the techno equivalent of streaking. Others detect a ‘social revolution’ in the offing. Flash mobs are worth paying attention to. They offer a lesson about the evolving nature of networks: from Friendster, a six-degrees-of-separation dating service, to the ‘relationship mining’ software that combs through employees’ electronic address books to identify which of their contacts might be useful to the employer. What flash mobs do is make networks tangible.”