Can you make text content be part of a class?
For example I have a footer DIV with links to all of the many pages on my site. If I add a new page to my site and want to have it listed in my list of pages in the footer, then all of a sudden I have to add it to every single page.
What you want are server-side includes (SSIs) for site wide links.
Or use DW Templates to create your site pages. One template.dwt file will contain site wide elements that are globally populated to all child pages spawed from that template.
What bregent said.
Set up all your repetitive page elements (headers, footers, navbars etc) as server side includes. You can have multiple SSIs on every page.