Adding a simple tab view, nothing fancy just easy.

tab_view.html.haml

-# File: application.html.haml
-# Include YUI in your head

=yui_loader_includes

-# File: _tab_view.html.haml
-# To use a component in one of your views, call yui_require
-# Components are loaded using the yui loader, dependencies are managed
-# Any code added to yui_script filter will be rolled into single init function and outputted with the loader

-yui_require :tabview
:yui_script
  UI.demoTabView = new YAHOO.widget.TabView('demo_tab_view');

#demo_tab_view.yui-navset
  %ul.yui-nav
    %li=link_to tag(:em, 'Details'), '#tab_details'
    %li.selected=link_to tag(:em, 'Content'), '#tab_content'
  .yui-content
    #tab_details=render :partial=>'details'
    #tab_content=render :partial=>'content'