There are a couple of different programs from this vendor that will allow you to capture a screen demonstration with or without an audio track, and then create an avi output file that you can publish (see autoscreenrecorder). Also, some snapshot captures and animators.
This is a fun site that you can use to create a cartoon. I have used this for my teach back and it has received great reviews. Takes some time to get acquainted with it. But for those that likes a creative side of presentation, here it is.
Explain Everything is an easy-to-use design tool that lets you annotate, animate, and narrate explanations and presentations. You can create dynamic interactive lessons, activities, assessments, and tutorials using Explain Everything's flexible and integrated design. Use Explain Everything as an interactive whiteboard using the iPad video display (via Airplay/cable).