Free alternative to Macromedia Captivate and Camtasia Studio

"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."

It basically allows you to capture what's on your screen and saves it as a Flash .swf file for sharing, especially on the web.

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