When using digital media it can be problematic to write maths, chemistry or physics equations and formulas. A few years ago I attempted to create a series of Power Points for my physics class and eventually gave up - writing formula and equations were all too difficult. I even bought a graphics tablet and found that my somewhat mediocre handwriting looked even more mediocre when digitised. To add insult to injury the next upgrade of Office did not integrate with the tablet software, so the tablet was a complete fizzer. I went back to overhead transparencies, however I fear that the humble overhead projector may be an endangered species.
Microsoft Word has Equation Editor - but what happens if you are not using Word? What if you want to use PowerPoint, Open Office, Google Docs, Google Sites, blog or another format? Open Office has only the most rudimentary equation editor. You can use software like FX, however I don't find the user interface intuitive and it costs money.
This is where LaTex Online Equation editor (pronounced "latek") comes in handy. It provides a free, intuitive interface where the equations can be downloaded as a gif or generates html code that you can embed. The real functionality is that you can drag and drop straight into a document such as a Google Doc or Google Presentation - EASY!
I generated the Law of Conservation of momentum very quickly...
You can also generate chemical formulas
If you are comfortable using equation editor then you will find the interface familiar. Share the link with students so they can improve their assignments and practical reports.