Jing is a free tool from TechSmith that allows you to capture the screen on your computer to create a video tutorial. You do have to record your voice to narrate your video tutorial, but after a little practice this becomes more comfortable.
Here is a Jing tutorial created to demonstrate how to upload a PowerPoint slide to a shared GoogleDoc Presentation.
To learn more about Jing, go to
Jing, by TechSmith