A site to view and share educational material made of small knowledge chunks called modules that can be organized as courses, books, reports, etc. Anyone may view or contribute. The site provides access to high quality courses, course modules, and stand-alone learning activities in numerous disciplines.
A learning module on photosynthesis enhanced with colorful graphics, questions for review, and additional links.
Students use a virtual protractor to measure a variety of angles after going through a short introduction of how to use a protractor.
The Why Files is a great site that discusses the science behind the news. It's well written, with lots of great images, and there's also a page about classroom activities.