Software engineers spend a considerable amount of time on program comprehension. Although vendors of Integrated Development Environments (IDEs) and analysis tools address this challenge, current support for storing and sharing program comprehension knowledge is limited. As a consequence, developers have to go through the time-consuming programing understanding phase multiple times, instead of recalling the knowledge from their past or other’s program comprehension activities. In this paper, we aim at making the knowledge gained during the program comprehension process accessible, by combining two sources of information. Inspired by the success of Twitter, we first of all encourage developers to micro-blog about their activities, telling their team mates (as well as themselves) what they are working on. Second, we combine these short messages with automatically collected interaction data on, e.g., classes, methods, and work products inspected or modified by developers. We present the underlying approach, as well as its client-server implementation in an Eclipse plugin called James. We conduct a first evaluation of its effectiveness, assessing the nature and usefulness of the collected messages, as well as the added benefit of combining them with interaction data.