The recovery of post-Katrina New Orleans has unleashed a new generation of social entrepreneurs. A sterling example: the Broadmoor Improvement Association and its dynamic president, LaToya Cantrell. Broadmoor is a racially mixed, middle-class historic district dating to the 1920s. During Katrina, it saw 7 feet of flooding. The venerable association found a new mission after the storm, when much of the area was in danger of demolition and rezoning as green space. Neighbors collaborated with researchers from Harvard's Kennedy School of Government and students from Bard College on a comprehensive development plan. More than 70% of the area's homes have been restored. The group successfully lobbied for better police presence and emergency services, reopened their local school as a charter, and built a new playground. Besides fostering exceptional cohesion -- broadmoor lives! signs are on every lawn -- they've become a model: Cantrell has spoken around the country about the power of community.