According to Barab "et al." (2004), the ideal community of practice (CoP) is a "persistent, sustained social network of individuals, who share and develop an overlapping knowledge base, set of beliefs, values, history, and experiences focused on a common practice and/or mutual enterprise" (p. 55). Thus, a CoP has a social purpose of supporting peers and colleagues by sharing knowledge and artifacts that serve authentic practice. E-portfolios, online versions of longstanding practice in teacher education, would appear to be ideal candidates to undertake such a task. Nevertheless, the authors argue that conceptual and practical issues must be addressed before significant changes can occur. In the end, a healthy critique of the conceptual and practical aspects of supporting communities of practice online will result in more authentic, effective training of our next generation of teachers.