The authors discuss the notion of Rapid Collaborative Knowledge Building (RCKB) in classroom settings. RCKB seeks to harness the collective intelligence of groups to learn faster, envision new possibilities, and to reveal latent knowledge in a dynamic live setting. It is characterized by the notion of rapid cycles of knowledge building activities in a face-to-face setting. The authors propose nine principles for the design of collaborative learning activities in the classroom that foster RCKB, five of which are adapted from Scardamalia's knowledge building principles (Scardamalia, 2002). The context of their work is design research on introducing RCKB in a classroom with the use of a network technology called GroupScribbles. The technology enables collaborative generation, collection, and aggregation of ideas, and empowers teachers to design new collaborative and group learning activities in a classroom setting. The authors present two actual classroom lessons with collaboration activities which demonstrate some of the design principles at play. (Contains 7 figures.)