Most of this will be old news to those in search engine biz.

Adam Lasnik offered a post about Best Uses of Flash. He mentioned that Google is able to read the content of flash file but not all forms of Flash.

Try to use Flash only where it is needed. Many rich media sites such as Google’s YouTube use Flash for rich media but rely on HTML for content and navigation. You can too, by limiting Flash to on-page accents and rich media, not content and navigation.

It means if you use flash movie in your site, then you moved away from the search engine friendly site and your site will get low search traffic after put it up.