Can "Information Age" learners effectively multi-task in the classroom? Can synchronous classroom activities be designed around conceptually related tasks, to encourage deeper processing and greater learning of classroom content? This research was undertaken to begin to address these questions. In this study, we explored the use of instructionally-related instant messaging (IM) discussions during undergraduate university lectures. Over the course of three weeks, students practiced with and then employed hand-held computers for brief, synchronous class discussions in response to assigned questions related to the lectures. Students were observed during these sessions, and students and the instructors were interviewed separately afterwards. The contents of students' discussions indicate that they were capable of engaging in on-task discussions and of expressing opinions and exploring instructionally relevant topics. However, even though students routinely multi-task in classrooms as they attend to lectures, process the contents, and record notes for later study, both students and the instructors expressed some discomfort with discussion occurring synchronously with classroom lectures. In this paper, we describe student discussion behavior, and reflect on possible applications of multiple sequential (rather than simultaneous) tasks during classroom instruction. (Contains 1 table.)