Wink. Very cool Flash based freeware.

‘Wink is a Tutorial and Presentation creation software [sic], primarily aimed at creating tutorials on how to use software (like a tutor for MS-Word/Excel etc). Using Wink you can capture screenshots of your software, use images that you already have, type-in explanations for each step, create a navigation sequence complete with buttons, delays, titles etc and create a highly effective tutorial for your users.’