Getting Folders on Windows Phone 8 - With "App Folder" (MyNokiaBlog)
MyNokiaBlog posted this video demo of the new App Folder app by Nokia, which works equally well on GDR2 Amber devices, and does not need GDR3/ Nokia Black.
The app can be useful for organizing an over-long Start screen, but I suspect one should equally be unpinning apps which are not being used regularly.
Find the app in the Windows Phone Store here.