CHRISTINE GREENHOW is a postdoctoral associate in the College of Education and Human Development at the University of Minnesota, 125 Peik Hall, 159 Pillsbury Drive, Minneapolis, MN 55455; greenhow@umn.edu. Her research focuses on how people learn, teach, and collaborate using emerging social digital technologies (www.cgreenhow.org). She is currently leading a study of adolescent learners’ knowledge development, literacy, and community formation within and across two designed online social media spaces. She is the winner of the 2008 University of Minnesota Outstanding Postdoctoral Scholar award.