The Lab's X-Reality Working Group explores the fluid merger of "real" and "virtual" worlds, looking broadly at "cross reality" at several levels of scale. Researchers will develop innovative, core technologies that go well beyond mimicking physical spaces in virtual landscapes, and will architect new platforms and environments that seamlessly scale, from ambient to immersive, the blend between virtual and real. They also address issues of identity: developing technologies that allow virtual constructs to understand who we are and how to interact with us, in real time, at a highly personal level and through appropriate channels. Projects include, but are not limited to: developing and deploying agile, multimodal sensor networks; advancing extremely low-cost, ultra-low-power localization and embedded sensing technologies; building technologies that metaphorically map the real onto the virtual through immersive 3-D environments, such as Second Life; adaptively scaling the user's immersion depending on the available interface affordances and dynamically determined context; and developing next-generation, dual-reality avatars and interfaces. This effort takes a broad perspective, examining how this new, merged environment can become an extension of human perception, augmenting our five senses beyond the "here and now."