The youngest we ever did was the one week Univ of Denver summer program for 4th-6th graders (Rocky Mt Talent Search/CITY) when my DS was 9 yrs old. Now we're trying the 5th/6th grade program through Jhu cty for my 10 yr old that is 3 wks long.
My older dd did that same Discovery Program at DU when she was 9 as well (Marine biology course). She's wanting to try out the Marine Lab in North Carolina in the next few years if possible. Budget is going to be a concern with that one, though, since we'd have to fly her there (and an adult to get her from Charlotte out to the coast) as well as paying tuition.
