If you are going to load HTML as a header, or you want a header, footer etc. You might consider sub-classing the Page Class and creating a template page. That way all of your pages can use the same header, footer, side-navigation etc, and you won't have to worry about updating a ton of pages if your graphics or header changes.
Frames work well, but with templated pages you don't have to worry about maintaining the different frame pages, and if it is a public site the search engines won't have problems indexing it.
Jonathan Goodyear has a good templating solution, along with Paul Wilson's as well. With some pretty minor tweaks, I was able to modify Goodyear's to use for our sites Web applications.
Here is the forum where Templating is discussed:
http://www.webmatrixproject.net/Forums/ShowPost.aspx?tabindex=1&PostID=4692I can't seem to find a link to the code for all of the Templating code, but you can probably email Goodyear his website is
http://www.angrycoder.comIt may be too robust of solution for you. But it is just an idea.
Morgan