"An award-winning source for standards-based classroom resources in science, technology and engineering, from NOVA and other public television series." A free digital library associated with PBS provides teachers with downloadable video & audio clips that are aligned with education standards. Scientific topics include earth science, geography, life science, etc.
NASA home page has loads of science and technology based information, that is put into a graphical and interactive format. It covers a wide range of topics beyond space related topics.
The home page for the Discovery channel. It is a wonderful resource for science and tech interactives, videos, and images. A great place to find recent issues and topics in conservation and environmentalism.