Sketchcast is a great little tool which allows you to record yourself drawing a sketch – whether roughly with a mouse or more accurately with a graphics pen – and you can add audio commentary too.
Here’s a great example from Anecdote, explaining how communities of practice can be used to create action and outputs. I hope it embeds ok – one of the few limitations of WordPress is in the way that embedded media works, it often messes up the layout of the post unless you use a plugin to handle it for you. Hopefully there will be a Sketchcast plugin for WordPress soon.