In today''s knowledge based economy, successful companies are those that constantly acquire new knowledge and disseminate it throughout the organisation, and quickly embody it in new technologies and products. Previous research has firmly established the significant role of social networks in facilitating these knowledge flows, particularly in research and development (R&D) settings where the importance of optimal knowledge flows has long been stressed throughout the study of the innovation process. However, the recent prevalence of Web-based communication technologies, such as online forums, search engines, email, blogs, and wiki, have dramatically altered our understanding of what constitutes a social network. Underpinned by the technological gatekeeper concept, this study examines how the digitization of the social network, and the resulting interplay between its online and offline components, have impacted knowledge flows in modern R&D groups. This analysis will be of interest to researchers and practitioners concerned with innovation and knowledge management in R&D firms.