Twitter can be used at conferences to (1) connect with attendees, (2) find conference information quickly, and (3) participate in the "back-channel" discussion. The document discusses how Twitter was used at the Interaction 09 conference, including strategies for live-tweeting sessions, promoting the conference to non-attendees, and reflecting on the conference afterward. While session-specific hashtags saw little use, #ixd09 became the main conference hashtag, and the Twitter stream provided value for attendees and non-attendees during and after the event.