ASP.Net MVC return xml result similar to 37Signals' Highrise API

[Harkunlouseg]

I was wondering how would one go about returning XML as a result using ASP.Net MVC when the user enters the following url:http://www.mysite.com/people.xmlIf the user enters http://www.mysite.com/people the normal html view should be rendered showing all the people in the database whereas if they add .xml they will get xml containing all the people in the database. The 37Signals' Highrise API works this way. I know I can use XmlResult but, how would I configure the action to return the normal view if the user does not specify .xml at the end of the url?