Great websites

Recently I discovered or someone gave me the link with a great websites.
Let's talk about this two sites:

1) http://www.malakfunsci.com/Ele_chem/solar_cell.html
Malak Fun Science is a website with a lot of experiments about Physics and Chemistry, its explanation and easy to learn. Also it has toys and games. Anyone can contribute with more experiments. I think this website can grow up a lot, because the experiments are made in a very easy way, with cheap materials.
2) http://www.buzzle.com/articles/physics-formulas-list.html
A great website with a lot Physics' formula.
Add to your bookmarks to find quick a Physics formula.