Mobile devices like smartphones and tablet PCs are widely used among university students and can be used for audience response systems (clicker systems) to improve teaching. Modern implementations of these systems are no longer limited to plain multiple-choice questions, but enable the lecturers to perform a variety of teaching scenarios. We present and discuss two novel extensions for audience response systems, namely "message boards" and "teacher controlled self-learning tasks." In the former, students can use their mobile device to make comments and ask questions related to a lecture, which are then discussed directly during class. The second extension can be used to build multi-stage learning and exercise scenarios that accompany the lecture. These two techniques bring new pedagogical and technical questions with them. We discuss their large potential and point out some pitfalls we have encountered in our experiments. [For full proceedings, see ED571332.]