I use comment tags to hide certain parts of coding that have become obsolete on a web page, but which may still be used in the future, such as a link to a site under construction. Time and time again, you find websites that have keywords galore repeated in the title of their website. The title should contain keywords but in a classy way. The title is the first thing users will stumble upon in the search engines - make it relevant. Frames Okay, maybe never is a little harsh, but you really should keep your frames to a minimum.
Search engines have a very difficult time reading frames and frame links.