This is just the first of many new video tutorials on Flash CS3 (and the upcoming Flash CS4) and Actionscript 3.0.
Summary of the video tutorial:
Using Nested Animations in Movie Clips with Flash CS 3
By: Santo Romano
Tutorial level: Beginner to intermediate Flash users.
Flash version: Flash MX, MX2004, CS2, and CS3
When creating simple animations in Flash, the main timeline is often the best place to position your animations. However, when these animations are repetitive, the best way to handle them is to utilize the movie clip symbol in Flash. Unlike the other symbols you’ll find in the Flash environment, the Movie clip symbol is perfectly suited to handle this kind of work. Rather than creating multiple key frames over and over again, it is much better to nest the simple animation inside of a Movie Clip, and to let it handle most of the work.