By default the command line outputs are displayed onto a screen, but you can easily redirect into a text file or even make it to be used as an input for the following command.
Pixlr is a free and probably the best web based image editor. I will show you how to open and and resize an image, I'm sure you will be impressed how well the web app actually works.
If you want to use only a song from a specific video, you can use it with the help of web converter. In this lesson I will show you how you can convert Youtube video to mp3 file.
If you don't have installed program for editing PDF documents on your computer, then you can use web application PDFescape which allows you to edit your documents in your browser.
If you found yourself in a position where you wanted to crop a certain photo into a perfect square but you just couldn't figure it out how, than this tutorial is for you.
Some installations or settings changes require you to restart your computer. In most cases you don't need to actually reboot it, you only need to restart the explorer.exe process.