I have kind of rigged things so that my topsite can show up as a widget on one of my content sites. Then, I have the URL of the topsite point back to the content site. Its a decent way to build links to a content site. Basically what I have done is create a VERY streamlined template for use on widget.domain.com and a full blown version on rank.domain.com. The widget.domain.com topsite is then placed in an iframe on the main site at domain.com.
If these is some interest in this, I will try to make a mod and step by step guide.
If you want to see it in action, you can check it out at http://www.aquariumlife.net