Wink

Have you seen this software?

http://www.debugmode.com/wink/

Wink is a Tutorial and Presentation creation software, primarily aimed at creating tutorials on how to use software (like a tutor for MS-Word/Excel etc). Using Wink you can capture screenshots, add explanations boxes, buttons, titles etc and generate a highly effective tutorial for your users.

Let me know if you use it and how you like it.