Pen-based technology provides new means for interfacing with digital computers. At Purdue University, we have been developing courses that allows computer science undergraduates to explore non-traditional human-computer interfaces, to implement complex working systems, and to give them hands-on experience in developing team projects. After the first two years, we have successfully implemented a multitude of pen-based applications, across a wide-range of areas. In this paper, we present a summary of the course organization, projects, evaluations, and future directions.