Kapil posted a great article about a new tool created by Stephanus Schulte and Jean-Pierre Regente. It's an Azure-hosted tool that keyword searches Group Policy settings. Read about it here: http://blogs.technet.com/b/askds/archive/2010/06/24/announcing-the-group-policy-search-service.aspx
Check it out here: http://gps.cloudapp.net/
Here's what it looks like in action:
Go forth and discover!