def index
      respond_to do |format|
        format.xml  { set_posts_for_feed }
        format.rss  { set_posts_for_feed }
        format.html { set_posts_for_index_page }
      end
      yield(posts) if block_given?      
    end
def index
      respond_to do |format|
        format.xml  { set_posts_for_feed }
        format.rss  { set_posts_for_feed }
        format.html { set_posts_for_index_page }
      end
      yield(posts) if block_given?      
    end
Handles GET requests to /blogit/posts.html, /blogit/posts.xml, and /blogit/posts.rss
 Possible formats include:

 "XML" -  calls {#set_posts_for_feed}.
 "RSS" -  calls {#set_posts_for_feed}.
 "HTML" - calls {#set_posts_for_index_page}.

 Yields #posts if called with a block (useful for calling super from subclasses)

 Returns nil