Over the next few weeks, dozens of schools will open across New Orleans for the second full academic year since Hurricane Katrina. As many as 33,000 children are expected to report to one of the campuses in the city's patchwork of charter and traditional public schools. Since the hurricane struck two years ago this month, New Orleans has become a laboratory for innovation. By the end of the 2006-2007 school year, nearly 60 percent of the city's 26,000 schoolchildren were attending 31 charter schools, the largest share in any city in the nation. Nine new charters, in fact, are slated to open in the new school year. Still, the state-run Recovery School District, or RSD, is expected to operate more than 30 schools this year and will remain central to rebuilding public education in the city.