Sitecore 7 patch:source

One of my favourite new features in Sitecore 7 is actually a fairly small, seemingly insignificant one. If you browser the config viewer(/sitecore/admin/showconfig.aspx) in Sitecore it will now show you which config patch settings are applied from.

<sitecore>
 <events timingLevel="custom">
  <event name="item:deleted">
   <handler patch:source="Sitecore.Analytics.config"/>
  </event>
 </events>
</sitecore>

Now if you have ever worked on a project with a lot of config patch includes related to various modules, this can be extremely useful.