Twelve years after the first charter school was launched, the charter school movement is now entering its adolescence. Like many pre-teens, it's had its share of growing pains, but I am confident that it is about to hit a growth spurt. That is because charter schools are enormously popular with their primary clients --parents and students-- and because they are starting to show promising results in terms of student achievement. The basic tenets of charter schools-give them room to be innovative, hold them accountable for results, and let parents decide if they meet the needs of their children --are perfectly aligned with the historic No Child Left Behind Act (NCLB), which also focuses on accountability for results in return for more flexibility, and with providing more options for parents than ever before.One of the promises of charter schools is that they can serve as laboratories of innovation --they can be public education's "R&D" arm. Because they have greater autonomy than traditional public schools, and since they tend to attract pioneering educators, they can try out new approaches to education that, if proven effective, can be transplanted back into the larger public education system. It is in this spirit that we highlight eight of the most successful charter schools in the United States.These schools were chosen after an exhaustive national search. They were primarily selected because they have demonstrated success over time in boosting student achievement. Surely many more charter schools could have been identified, and these should not be considered "the best" charter schools in the nation. Nevertheless, they are among the best, and each has much to teach other charter schools --and traditional public schools-- about teaching and learning, management strategies, staff development, and many other topics.