And a Software I use a Lot, Screenflow
We have been running this series of excellent posts by Rebecca Leaman on getting your PowerPoint presentation up on the web. Another way that I have been using lately if you are on a new Mac is to use the new Screenflow software.
Screenflow allows you to record the screen plus adding in a video track of yourself. Great to adding commentary and a personal touch to your presentations. Screenflow also allows you to edit out parts you don't want, very helpful. I have been using it to record How to Videos for my software that I do in PowerPoint. Once complete you can then save them as .mov files and load them up onto Youtube and other video hosting platforms. Once there they can be linked to your blog or website.
Screenflow is made by Varasoftware. www.varasoftware.com/products/screenflow/