If you are looking for a different way to add a presentation to your blog or online class, SketchCast might be worth a look. It is a browser-based tool which allows you to record your drawings or text and record audio along with what you are putting in SketchCast window. The videos are hosted on the SketchCast site, so you can easily embed them into your site. Here's the demo:
Tools and tips related to online and distance learning and using technology in instruction