Video modeling is a great tool for helping students transition from one activity to another. See an example of this for hallway transitions between classrooms here:
Title: Seeing Is Believing: Video Self-Modeling for People with Autism and Other Developmental Disabilities
Book Description (from Amazon.com): Video self-modelling (VSM) is a proven and effective method for teaching new or more advanced skills and behaviours to people with autism. The technique uses home-made videos (created by parents, teachers, or therapists) to demonstrate a desired behaviour. The key feature of any self-modelling video is that the person modelling the behaviour in the video is the same person watching the video. VSM allows a person with autism to see himself performing the very skill he is trying to learn. This is accomplished through careful editing and manipulation of video footage, transforming it into a cohesive teaching tool. And the process is a lot easier than you may think! This book begins with an overview of the research and science behind VSM and insights into why it is a particularly good teaching method for people with autism and other developmental disabilities. It then explains the process of making self-modelling videos from start to finish, including how to: choose the behaviour/skill to teach; conduct a task analysis; select and use camcorders and video software; storyboard video scenes; plan and shoot footage; transfer the video to a VCR, DVD, or computer; edit and manipulate the footage; and, keep track of and interpret data. These videos can teach or modify a wide variety of behaviours and skills, such as controlling tantrums, increasing the frequency and length of verbal responses, making requests, interacting with peers, and solving math problems.