A friend's son did the "Be a scientist" last year and loved it; he is returning this year with my son for the "Inventions" session. We have heard nothing but good things about the CTY summer sessions. It is true that the 3 week session is not cheap ($1495), but I am paying $425/week for non-CTY camp sessions (e.g., at Congressional) so it's not far off of the scale for summer camp in the DC area.