SOMWeb is a Web-based system designed to support a clinical community of practice. Their collaboration centers on the discussion of oral medicine cases at monthly telephone conferences. SOMWeb facilitates the collaboration by, e.g., providing forms for entering case data and by providing easy access to current and previous cases. Through interviews, log analysis, and analysis of cases several impacts on the collaboration can be identified. These include the impact on membership, case submission, chairpersonship, and the community of practice as a whole. Further, it can be concluded that the rhythm provided by the telephone conferences ensures that the system has regular use.