Future City competition: Project-based learning program for middle school students to build futuristic cities. Future City Philadelphia link.
Rocketcontest.org: The Team America Rocketry Challenge (TARC).
Nar.org: National Association of Rocketry, NAR rocketry competition.
American Mathematics Competition by Mathematical Association of America.
The Math League
Links to web resourses for Computer and STEM education by Vodien.
Cty.jhu.edu: The Johns Hopkins Center for Talented Youth. List of academic competitions.
Giftedandtalented.com: by Stanford University
Davidsongifted.org: Davidson Institute for Talent Development website. They maintain Gifted issues discussion forum and Davidson gifted database of resources.
Smartscholar.com: computer science resource page.
Study.com: student resource to study, improve grades, test prep or even get accelarated college credits. Free trial available but other wise monthly tution to acess the materials.