One task I had to do a a few times recently is track down which GPOs had a particular setting enabled. If you are working in an environment with a signifcant number of GPOs this can be a tedious task.
The easier way - use the SDMSoftware GPMC cmdlets to create an XML file for each GPO. You can then use select-string to search through the GPOs for the setting you need. The real advantage that searching is so quick that you can have multiple attempts to refine your search and still do it much quicker than checking manually in GPMC.