There are many tools available to organize media, audio mainly, files. Mp3Tag and MediaMonkey being just two that support tagging music files among other features. One area that is not as populated is a desktop application that supports tagging files of any kind.
Ultrafolder, now defunct, was one such promising application. Upon installation a shortcut would be placed on the desktop and any file, be it music, word or image that was dragged to the shortcut would launch the program and allow the addition of tags. The only negative aspect that I can think of was that all the tagged files would reside in a single folder, otherwise I found it very useful and bug-free. Ultrafolder existed for a while under an expiring beta @ ultrafolder.com, but after the author discontinued development, due to lack of interest as he put it, the executable would only prompt for an update check and no longer launch. A very unfortunate decision by the author in my opinion.
In my search I have come across another app, it is called tag2find. Its development seems to have slowed since it initial launch and even though it is promising and with more features than Ultrafolder it has the disadvantage of needing to run in the system tray to monitor folders and also needing to be installed as a Windows service. It does have advantages, of course, and among them is the ability to move any tagged files and since it runs on a NTFS volume the meta information is easily carried over.
My search for similar apps continues, if you know of any please leave a link and a comment.