Continuing progress in microelectronics has allowed the embedding of sensing, processing, and wireless communications capabilities in familiar physical objects. This enables the creation of smart environments, where communication and computation technologies facilitate interactions between people and their surroundings, instead of just person-to-person or person-to-server communication. In a collaborative project underway at the University of California, Los Angeles, called Smart Kindergarten (SmartKG), we are exploring these technologies in a sensor-instrumented environment for early childhood education. Spatially dense but unobtrusive sensors continuously capture interactions among students, teachers, and common classroom objects. The sensors deliver observations wirelessly to a wired infrastructure for analysis and storage. Two crucial building blocks of this environment are Sylph, a sensor middleware infrastructure, and iBadge, a lightweight sensor-instrumented badge worn by students and teachers.