Screencast-o-matic is a tool for videotaping your computer screen actions. Imagine that you want to show students how to navigate a website but aren't able to get them all together for a live demonstration. With Screencast-o-matic you can make a recording of you navigating the website, audio included, and post the video to your website, blog or email it out.

Here's a screencast I did explaining how to use Google Talk: