This report offers lessons from the last in a series of three high school reform conferences sponsored by MDRC, the Council of the Great City Schools, and the National High School Alliance. The conference brought together leaders from 22 midsize urban school districts on June 25-26, 2007, provided a forum for practitioners to share research and practice-based lessons about helping students transition successfully into high school, stay on track to graduation, and be prepared for moving into postsecondary education, training, or the workforce. As described in this report, the reform measures that districts have adopted in response to these challenges cluster into three categories: (1) Personalization (supplying individualized attention and personalized options that respond to student needs and choices); (2) Academic rigor (delivering a demanding yet accessible curriculum that engenders critical-thinking skills as well as content knowledge); and (3) Postsecondary preparation (making possible a smooth transition from high school to the world of higher education and work by providing students the guidance and understanding they need to be admitted to and succeed in college.) Although many of the steps districts have taken are geared toward changing the classroom and the school, conference participants also acknowledged the importance of changing their own actions as well by applying system-level pressure and providing overarching support aligned with classroom- and school-level goals. The report concludes that challenges faced by high school districts are not likely to dissipate, and district leaders cannot put on hold actions to address them while they await rigorous evidence. Three broad areas in which practitioners have experienced promising results although the research base is incomplete and inconclusive were identified: (1) Small learning communities (SLCs) as the foundation for instructional change; (2) Teacher quality; and (3) College preparation programs. Investigation into these areas could provide valuable information to education policymakers and administrators. [This document was written with Julia Bernstein and Laura Sztejnberg.] (Contains 24 footnotes.)