Here is the result of playing around with Ruby, WIN32OLE, and the iTunes COM library:
Download iTunesTagger.rb 0.1
What this thingy will do is allow you to treat the arbitrary “grouping” field as a comma-separated list of “tags”, thus allowing you to tag files as you would bookmarks at del.icio.us. This can aid in creating smart playlists. Trust me.
“Wait!” I hear you snark, “you can already do that in iTunes!”
Well, yes, you can, but unlike iTunes, this tool will let you treat the grouping field as a list. Thus, if you want to remove or add a single tag to all of an artist’s songs (e.g. add the tag “explicit” to, oh, say your entire N.W.A. collection1), you can do that with this tool regardless of whatever fields were already set in the grouping field. In iTunes’ tag editor, this field is treated like one big string, so a bulk operation will replace the contents of the field entirely, which isn’t quite what you wanted to do if you had different tags across the bulk operation.
Anyways, it’s a first go at something useful. You’ll need Ruby (natch) and a recent vintage of iTunes for Windows2. I’d recommend you read the comments at the top of the program, you early adopter, you.
1 What do you mean you don’t like “Straight Outta Compton”? Sucka.
2 This program could be modified to work with Ruby’s WAEOSA support under Mac OS X. I may just do that, since my main library lives at home on my iBook.