Engagement in communities of practice has increasingly come to be seen as an important aspect of adult learning. Participation within such communities is thought to provide a dialogic space in which learning can take place. These ideas are increasingly being applied to the work of teachers, lecturers, and trainers. This reflective paper addresses a number of issues: firstly, it locates communities of practice within a discussion of situated cognition and "mode 2 knowledge". This is followed by an engagement with Lave and Wenger's notion of communities of practice and situated learning. There is an affinity between these ideas and those developed by David Hargreaves, particularly his discussion of on-line learning communities and "teacher tinkering". In a number of respects these arguments are couched in overly optimistic and progressive terms. The concluding section seeks to raise a note of caution, considering the limits and possibilities of the previous arguments for the development of progressive and transformative educational practices, with the application of Gramscian ideas that call for the wider politicisation of practical education. (Contains 1 note.)