This article explores the phenomenon of online based teaching and learning in schools - an innovation in German school pedagogic since a few years. Two key factors need to be considered: firstly, pedagogical forms of mobile learning, and secondly, teachers' classroom preparation using online distributed learning materials. Those who approve mobile phones as cultural resources of learning argue that today every student has a mobile of his own and uses it all day lang, and that - therein - there are lots of hidden resources for learning like situated learning, collaborate learning, conte.xtual learning, experimental learning, informal learning, or whiteboard learning. Learning within the mobile space accepts and takes into account the media culture of children and young people today. Those who approve online materials for teaching preparation argue that teaching with the help of textbooks is not modern and relevant enough because of their cultural lag. Besides it takes much more time to plan traditional te.xtbook lessons than to download and copy internet preparations that generally are very weil designed. Even if the influence of mobile and internet is very great today there are however other factors which should not be ignored: on the one hand real learning is not of hurried nature and fleeting, and on the other hand online teaching materials are produced in the interests of their authors or of a lobby, and possibly they are not in accordance with the aims of school education.