Although Flash is a highly sought after medium for websites these days, it may not be the best for search engine optimization. Think of website text as food for a search engine. Search engines 'feed' on many different things, but the most important thing is the keyword rich content. Flash does not provide text-based content for search engines to spider, thus it needs to be used in moderation and in places which still allow good amounts of content to be seen by the search engine spiders.

However, on July 1st 2008, Adobe announced it is teaming up with search industry leaders (like Google and Yahoo!) to improve the search results of dynamic web content (like Flash) and rich internet applications. This means better indexing by search engines and a higher ranking (hopefully) for most flash websites.

This does not mean, however, that you should go nuts with Flash. From a design perspective, although Flash can give that “wow” factor people want, it still needs to be evaluated for effective website usability. Flash should provide "wow" within the context of the user goals for the website content. For example, our Citrus SEO homepage features a prominent banner for Flash case studies, to drive website visitors deeper into the website content.

My recommendation? Evaluate the use of Flash on a case by case basis to balance your SEO goals, business goals, and user goals for your website.