Amid budget cuts in U.S. public schools, the spotlight is on how to make less effective teachers more effective--fast. The authors describe virtual coaching--in which a coach interacts electronically with a teacher as a lesson unfolds--as a promising way to help teachers with weak teaching skills. Virtual coaching uses online and mobile technology (termed bug in ear) to allow a coach located down the hall or across the country to observe a teacher's lesson and offer discreet, running feedback through an earpiece the teacher wears. Rock and colleagues, who have worked as virtual coaches to dozens of teachers, describe how such a set-up can help struggling novices break through to solid teaching skills. Because the coach provides feedback, helpful criticism, and suggestions as a lesson progresses, virtual coaching can shape teaching, and teachers' awareness of their weaknesses, in a way traditional coaching can't. It also saves time and money. The authors discuss the skills and conditions needed to make virtual coaching successful, and the kind of technology and equipment both teacher and coach need to proceed (including sample prices). (Contains 1 figure.)