It took me a while, but ever since I've gotten my head around Smart Folders (and Smart Playlists and Smart Groups, etc.), I've started to think about the way I use my Mac a bit differently. Clearly iTunes is the winner in this regard (watch for an upcoming multi-part series about Smart Playlists on The Merlin Show), but the Finder, and Address Book, and Mail.app also have an amazing amount of powe