I would also recommend the CTY writing programs. My son did them several years ago and learned so much. He also made some friends in the class who he still keeps in contact with more than 4 years later. Just because the classroom is virtual doesn't mean that the student-to-teacher or student-to-student interactions are real and meaningful.
If you're kid likes to write and would like to see how they measure up against a higher standard, HEROES runs a Writing Talent Search (see
www.HEROESgifted.org). This year qualified students may participate in the final round via Skype.
If you live in NJ, HEROES has worked with Rutgers University to create sections of Basic Composition (355:100) and Expository Writing (355:101 aka Comp 101) that will use the same curriculum and standards as all other sections of these courses but use reading selections and assignments that are developmentally appropriate for students under the age of 16. These are 3-credit courses. The first of these special sections will be offered in Spring 2011. Students will need to take the Writing Placement Test which will be offered in December and again during the HEROES Conference in January. Go to
www.HEROESgifted.org for additional details.