The study examines how urban school principals lead schools that make a difference for children in challenging settings. This research delves deeply into the experiences of three urban public school principals in the School District of Philadelphia in Pennsylvania, who used technology as an avenue to improve educational options for their students. The primary question is, "How does a school principal transform the conditions, the systems, and the structures of an underperforming urban school to move it in the direction of the 21st century?" The study also asks, "What is required to lead schools that are intended to be innovative in a highly bureaucratic organization?" This is a long-term, immersive, ethnographic study that takes place from 2007-2010 at the William H. Hunter Elementary School, the Science Leadership Academy High School, and the Microsoft High School of the Future. The central case study of the Hunter School is the practitioner action research of a principal who was appointed to a high-poverty neighborhood school with limited technology resources. The two supporting case studies took place in well-resourced high schools, considered unconventional because they were planned to improve student learning through public-private institutional partnerships, organizing learning differently than other district schools, and using technology in new ways for teaching and learning. Findings suggest that critical factors in designing 21st century next-generation schools are in the areas of leadership and technology practices. Making a difference for urban children requires school leadership which: 1) Manages transition and communicates purpose; 2) Understands how to manage in the context of urban schools; 3) Manages up to create the conditions for change; 4) Manages and increase resources; 5) Increases social, intellectual, organizational, and human capital; 6) Uses entrepreneurial skills and applies increased capital, and; 7) Prepares students for an uncertain future, which today includes using technology as a medium to accelerate the process. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]