This article, based on a collaborative research project on genetic knowledge production, examines the relations between on- and off-line field sites related to three heritable diseases: epidermolysis bullosa, chondrodysplasia, and Marfan syndrome. Field sites include the Web sites, listservs, and chat rooms run by lay health advocacy groups and biomedical professionals as well laboratories, clinics, and support groups meetings. The analysis uses the notion of location work, and the concept of the node that links different elements in a network, in describing a relational approach to multisited ethnography. The article presents three case studies that examine shifting locations between online and face-to-face relations, hyperlinks as a metaphor for interactive knowledge production, and the process of negotiating a networked ethics.