Spring 2016... A not-quite-random sampling of summer 2016 options for rising juniors and seniors (mostly)...

http://superscholar.org/scholarships/25-popular-college-scholarships/

https://www.dosomething.org/us

http://insideschools.org/free-programs 

https://www.nyu.edu/employees/life-wellness/family-care/child-care/summer-camp/teen-summer-programs.html

http://www.nyc.gov/html/dycd/html/youthlanding/teens_familylanding.shtml