While people attend presentations, panels, and lectures to learn something from the people at the front of the room, there's a lot of potential for creating spaces where audience members can interact with each other and the people presenting. This project focuses on augmenting the physical space of the auditorium to provide a venue for the audience to ask (and filter) questions for presenters. backchan.nl is a simple, Web-based tool that allows audience members to identify themselves, post questions, and vote on other people's questions. The current top questions are projected at the front of the room so that the audience can see them, as well as shown on a monitor visible to presenters. Upcoming posts are shown to users participating on the Web, but not on the main screen.