From a search engine optimization point of view, keywords rendered as images are worthless because Google can't "read" them. You won't get a boost in Google's rankings for content that the search engine can't read.
Flash can be similarly problematic. If you've ever tried to visit a website but were first confronted with a "loading" bar displayed on the splash page, you've experienced badly designed Flash. Flash is often used to create animated introductions, menu bars, or page transitions. Flash elements may look spiffy, but they can annoy users by taking a long time to load. Worse, content created in Flash is often ignored by search engines, except when implemented by a skilled SEO web developer.
If your website uses a clunky Flash introduction, get rid of it. If you want to use Flash sparingly for other aspects of your website, that's okay if done in conjunction with an SEO expert.
If your website presents headings as fancy .gif or .jpg images, tell your web designer to get creative with other imagery and style sheets so that slightly less fancy text headlines improve the search engine rank of your webpages.
