Dynamic and Media Rich Content Suggestions - Google Article

Along with images, many web designers like to integrate rich-media or interactive aspects into their site, often using technologies like Flash or AJAX.  While these can provide an engaging experience for users, Googlebot may have trouble discovering or following links on these sites.  For example, textual content is sometimes stored in Flash as images, making it difficult for Google to capture the words, much less understand the meaning of the pages.  With careful planning, however, sites can include dynamic and media-rich elements while still remaining reasonably accessible to users and Googlebot.  Consider structuring your site so that these elements are "extras," with your site's core information and navigation rendered in plain text for Googlebot AND all users without Flash.  This is otherwise known as "graceful degradation."  For additional useful suggestions, check out the two blog entries listed on this page.