We are often reminded that we remember little of what we hear and read but much of what we teach. The very act of teaching forces us to clarify our understanding and to process it so that it can be communicated in a structured, clear and accessible way. Here, Heather Scott describes how she got an initially reluctant Year 12 group at Challenge College to "teach" a similar group in a neighbouring school through the use of video. A clear structure to the task, a tight timescale and plenty of encouragement all contributed to a successful outcome for both the "teachers" and the "taught". Those at the receiving end were invited to respond with feedback and subsequently to send their own 'lesson' back to the students at Challenge College. An awareness of audience clearly raised the quality of the students' presentation and injected a healthy dose of competition into the proceedings…. [This article was written with Judith Kidd.]