Information Foraging: “Information foraging is the most important concept to emerge from Human-Computer Interaction research since 1993. Developed at Xerox PARC by Stuart Card, Peter Pirolli, and colleagues, information foraging uses the analogy of wild animals gathering food to analyze how humans collect information online.”
I think you could make a pretty easy argument linking the upsurge in weblog popularity to how well tuned they are to supporting effective information foraging. Add in good aggregators and perhaps we have the first hints of the knowledge economy equivalent of the transition from hunter-gatherer cultures to agriculture.