finding features in a content database in SharePoint 2010 using PowerShell or tools

Sometimes we have a feature id and we want to know the places where it is active, even as a dummy one. Below mentioned script might be helpful.

http://get-spscripts.com/2011/06/removing-features-from-content-database.html

or

http://featureadmin.codeplex.com/downloads/get/290833

or

http://archive.msdn.microsoft.com/WssAnalyzeFeatures