Students now routinely use computers to search the Internet, write reports, design presentations, crunch numbers, and make spreadsheets. The thing is, much of what they know and understand about computers and technology is most likely stuff they didn't learn in school. In this article, the author discusses how a San Diego school district is dramatically changing the way its students are taught. San Diego Unified School District (SDUSD) looks to transform teaching and learning through technology. This school year, the 133,000-student San Diego USD launched "the i21 initiative," which advocates say will reinvent the way local children are taught--and which could provide a model for other districts to emulate. The San Diego Unified i21 Interactive Classroom is an engaging and personalized learning environment designed to optimize teaching and learning through the interconnected use of auditory, visual, mobile computing, and formative assessment technologies across the curriculum. The first phase of i21 began this school year, with 1,300 3rd- and 6th-grade classrooms, mostly math and science, slated to be upgraded.