During 2003/2004, The Open University in the United Kingdom, in association with he BBC, will launch a wholly on-line continual professional development environment for teachers to be known as TeachandLearn.Net.  Focusing on the example of the materials developed for Design and Technology teachers, this paper will consider the rationale, design and learning purposes of this novel approach to teacher development.  The line of pedagogical development of on-line technologies from the Learning Schools Programme (see paper in PATT-11) to the current flexible Postgraduate Certificate in Education (PGCE) course, through to the proposed TeachandLearn.net will be explored