Here’s an example
Vodpod videos no longer available.
Jing is free and easily installed. When its running, a little sun appears in the top right of your screen. You can click it to get a capture widget up, and then easily create a screencast. You can also upload the screencasts you create to screencast.com. I also grabbed a bookmarklet from vodpod.com which allows me to easily post any video to a wordpress blog (this is how I got this screencast posted).