Google has a little-known feature that enables web site authors to tell the search engine about the structure of their site. ASP.NET 2.0 also now supports a way of representing the structure of a site in a map (we call it the site navigation system).
ASP.NET 2.0 out of the box supports easily surfacing the sitemap structure using HTML UI with the new built-in ASP.NET 2.0 Menu, TreeView or SiteMapPath control. This past Friday Bertrand from the ASP.NET team published a cool handler to expose it in the Google format as well.
You can read about it and download it here.
BTW -- if you want to learn more about the new ASP.NET 2.0 Site Navigation features, you can also check out some of my past blog posts on this:
Hope this helps,