Internet-supported school-university partnerships for teacher education and professional development offer new possibilities for teacher learning. This chapter presents socio-technical designs that stress the dynamics that come into play when people move from small-scale Communities of Practice or a local professional learning community to constellations of CoPs (virtual community). Three specific cases are presented, each one with its own level of internal coherence. Specifications regarding how design principles were applied are provided. These cases are all alternatives to conventional forms of teacher education and professional development. From day one, two of the three cases were endorsed as innovative endeavours by the participating institutions. The third is a contrasting case. Network-enabled CoPs and the encompassing virtual community can benefit from the organizational processes in place within learning institutions when it comes to issues of sustainability and expansion. Moreover, the collaboration across learning institutions, as exemplified by the network-enabled CoPs, is also beneficial to these institutions in terms of bridging the divide between theory and practice.