Creating an interactive, immersive experience is one of the hardest authoring challenges in human history. Success requires talent from computer science, engineering, art, drama, design, architecture, and a host of other disciplines. Science can tell us how and why to provide better perceptual phenomena (e.g. head-tracking), but success also requires "out of the box" thinking, rapid prototyping tools, and a willingness to create the grammar for this new medium.Since 1995, I have worked with Walt Disney Imagineering on several virtual reality projects for the DisneyQuest "digital theme park," now open in Orlando and Chicago. Meanwhile, Carnegie Mellon has recently created the Entertainment Technology Center (ETC), a joint initiative between Schools of Computer Science and the College of Fine Arts. As part of the ETC efforts, we have developed tools (available at http://www.alice.org) and processes that allow interdisciplinary teams of undergraduates to build and test compelling virtual worlds in a two-week time period. I will discuss the "Building Virtual Worlds" course, and the mechanisms we use to put students together from different fields.