title: How to retrieve configuration values immediately after they're saved
body: <p>I'm using a system.xml file to add a new section to to my Magento installation in <code>app/code/local/NameSpace/Module/etc/system.xml</code>. I've read that you can create an <code>IndexController</code> and override <code>postAction()</code> however of all the examples I've seen a custom layout is used rather than system.xml, is there a reason for this or can controllers be made to work for both of them?</p>
  
  <p>If they can't is there any other way to have a file run after the user clicks 'Save Config' so I can immediately start using the values with <code>Mage::getStoreConfig()</code>?</p>