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.

Diagramly

One of my students ask me about electronic circuit diagrams software and free in the internet.

Well, I found some really good stuff.

One software is TinyCAD. You cand found it in sourgeforge website. It's easy to use and free, but only gives a PNG output image.

Diagramly is an interesting schematic website. It bring us a easy way to create diagrams including circuits. You can export in XML, PNG, JPG, and SVG.