With mobile devices and wireless networks, new possibilities evolve to improve the interaction between teacher and students in class. The paper introduces the idea of DONUT, a Distributed annOtation tool for Notebook University Teachware, which is going to be developed within the NUSS (Notebook University Stuttgart) project being funded by the German Ministry for Education and Research. DONUT is integrated into an existing framework for application sharing. It is based on defining and making use of semantic relationships between presented teaching material and contributions of students. Hence, automatic categorization of contributions becomes available in advance. This supports the teacher's decision, whether to integrate contributions into the lecture or postpone them. Especially, a lot of questions regarding the same topic can indicate problems in understanding on the side of students quite well.