Microsoft hosts a site at gpscloudapp.net that allows browsing of all the options available with Group Policy, and then the exact policy is displayed, along with the corresponding registry key and value used by the policy (see screen shot below). It's a great tool to understand all the registry options and how they work.

  gpscloudapp

There is also a Windows Phone 7 application available called Group Policy Search that searches the same website for Group Policy settings.

To see more of John Savill's FAQS, check out his Windows IT Pro FAQs page.