How can I change the way MVC renders an action link dynamically?

I need to change the way MVC renders action links (and form and url, etc.) based on a config setting. I am writing a facebook application using MS MVC and my action links need to render the link like so:

<a href="/MyFBApplication/Home/Index/">home</a>

      

        
        
        
      

    

by clicking on the link above go to:
http://apps.facebook.com/MyFBApplication/Home/Index/

"MyFBApplication" is the name of the facebook application. To create a link, I started by calling

Html.ActionLink("Home", "Index", "Home")

      

        
        
        
      

    

When a user clicks on a facebook link, they'll make a request for this link under the covers:

http://www.myapplicationserver.com/facebook/123456/Home/Index/
(123456 is client id and required).

The response from here is then processed by facebook and displayed to the user as:
http://apps.facebook.com/MyFBApplication/Home/Index/

As mentioned above, facebook is asking for page data behind the scenes.
http://www.myapplicationserver.com/facebook/123456/Home/Index/

The problem is calling

Html.ActionLink("Home", "Index", "Home")

      

        
        
        
      

    

will display a link that will lead to http://apps.facebook.com/facebook/123456/Home/Index/

and I need this to lead to:
http://apps.facebook.com/MyFBApplication/Home/Index/

I got it right to build a new set of extension methods.

 Html.FacebookActionLink("Home", "Index", "Home")
 Html.FacebookBeginForm("Index", "Home")
 Html.Facebook(etc)

      

        
        
        
      

    

But it has a "smell". I would like to find a place where I can intercept the Html.ActionLink () plumbing in the process and change the output. Then I can use all the standard calls.

Thanks!