We used a trial version of Macromedia Captivate to create a Blackboard tutorial demo (attached as a Flash movie; you must be logged in to see the attachment below). Although this demo is still a bit rough (please pardon the voice), it was fairly easy to put together and took less than 10 hrs to make(would probably take even less for more experienced designers). Basically, I recorded the actions I wanted to demo, and then added different elements-- like title slides, more captions, and audio narration -- on top of the initial recording.
In our opinion, Captivate seems a very user-friendly...