Many young people learn a discouraging set of lessons between the ages of 16 and 24. They come to see secondary school as irrelevant, available jobs as demeaning, and their prospects and choices as diminishing. Some continue to "drop in" to school long enough to get a diploma, but leave lacking the skills or interest to pursue further education. Others drop out of school altogether. Seen in this context, the ambitious promise implied in the federal law to "leave no child behind" will require moving expeditiously beyond the "one-size-fits-all," factory-model high school to a far richer diversity of learning environments. This paper focuses on four types of learning environments that appear to hold particular promise for vulnerable and potentially disconnected youth: reinvented high schools, secondary/postsecondary blends, education/employment blends, and extended learning opportunities beyond the school day, year, and building. The first section paints a statistical portrait of the substantial number of urban youth who could potentially benefit from these new programmatic options. The second section describes the authors' process for identifying and investigating emerging, powerful learning environments, then profiles four programs that show evidence of effectiveness. The report concludes with a discussion of the policy opportunities today for creating multiple avenues for young people to achieve to higher standards, along with four specific policy recommendations to meet this goal.