The creation over the past decade of unanticipated applications of the Internet, such as web services, peer-to-peer file sharing, networked gaming, podcasting, and voice telephony, is resulting in a recent rethinking of the core Internet infrastructure and the original architecture choices. In this project however we propose to go beyond reacting to these applications that have already emerged, and proactively consider the network architecture implications of a new class of applications involving embedded sensing technology as it moves from scientific, engineering, defense, and industrial contexts to the wider personal, social and urban contexts. Today, applications are emerging which draw on sensed information about people, objects, and physical spaces. These applications enable new kinds of social exchange: By collecting, processing, sharing, and visualizing this information, they can offer us new and unexpected views of our communities. They require new algorithms and software mechanisms because unlike scientific applications of distributed sensing, a single system is widely distributed, intermittently connected, and privately administered; and unlike traditional Internet applications the physical inputs are critical to the behavior.