New social technologies offer new opportunities for creating online communities of praxis in the preparation of preservice teachers. In this design research study, 22 preservice teachers in a social studies methods class conducted online class discussions inside the National Council of the Social Studies Network Ning, a social network for social studies educators. These preservice teachers engaged in series of reflective dialogues blending theory and practice--the hallmark of praxis--with their classmates, with other preservice teachers from around the country, and with practicing social studies educators from around the world. They also expressed a strong intent to engage in professional learning networks and communities of praxis in the future, although the Ning was ancillary to these intentions. These findings both hold promise and offer crucial guidance for other teacher educators. When implemented with attention and intention, online social networks provide promising opportunities for students in teacher education programs to engage in networked communities of praxis that can provide opportunities for colearning throughout a teacher's career.