As Richard Rusczyk (math competitor and now operator of the Art of Problem Solving website) says, "If ever you are by far the best, or the most interested, student in a classroom, then you should find another classroom."

http://www.artofproblemsolving.com/Resources/AoPS_R_A_Calcul...

He has other good ideas for smart students in his other articles.

http://www.artofproblemsolving.com/Resources/AoPS_R_Articles...