The inspiration for this work comes from a research consultancy project aimed at assessing the use of the web to enhance communication between two groups, namely, teams of clinicians and the families of patients in Intensive Care Units (ICU). As this project unfolded, the challenge of enabling knowledge sharing between these two disparate groups was encountered. In the ICU situation the patient usually does not have the capacity to contribute to their healthcare choices so that decisions have to be made on their behalf using the combined knowledge of the clinicians and the patient's family. The situation is made more difficult by the adhoc nature of events experienced by the ICU staff and family members who happen to be present when time-critical decisions have to be made at all hours of the day and night. As a spin off from the main project, the potential for alternative modes of knowledge sharing between the two groups was investigated. The result of this process is the taxonomy of modes of knowledge sharing between groups that is presented and discussed in this paper.