It looks pretty, but search engines can't read those graphics. That means they miss out on text that might make your site more relevant. Some of the search engines will index ALT text and comment information, along with meta tags. But to be safe, use HTML text whenever possible. Some of your human visitors will appreciate it, also.
Frames can kill.
Some of the major search engines cannot follow frame links. Make sure there is an alternative method for them to enter and index your site, either through meta tags or smart design. Most search engines will index the other pages from your web site by following links from a page you submit to them. Don't bother submitting more than the top two or three pages. It doesn't speed up the process.