The paper presents a case study of the educational exploitation of group blogging for the implementation of a "learning by design" activity. More specifically, a group of students used a blog as a communication and information management tool in the University course of ICT-enhanced Geometry learning activities. The analysis of the designed learning activities, the blog content and log files, as well as the points of view of the students (via a questionnaire and a group interview) expressed upon completion of the activity gives significant findings supporting the researchers' initial hypotheses about the potential of blogs' educational applications. Blogs combined with a proper pedagogical approach such as "learning by design" enable teachers to offer high quality learning experiences to their students. (Contains 1 table and 3 figures.)