Looking to boost your SAT score, or to understand some aspect of physics that your teacher never properly explained?
Check out the Khan Academy. Its mission is to provide a world class education, for free, to anyone, anywhere. The Academy was founded by MIT graduate Salman Khan who has recorded thousands of videos on math, science, finance, and economics at khanacademy.org
The Academy currently offers thousands of videos on YouTube, with the goal of eventually providing a fully featured, free virtual school covering all major subjects. The current library offers a range of subjects from basic arithmetic to calculus, chemistry, physics, finance and SAT prep. There is also a web-app that generates practice problems.
Links:
http://www.khanacademy.org/sat
http://youtube.com/khanacademy
