Please... I need this, too... I work in Music Production, Graphic Design, Web Design and Photography -among others. There's no system of tags (as it is actually) that can help me to get my notes properly organized. I just need the ability to nest multiple notebooks. If I would do that with tags, that would be a terrible mess (not to mention that I can't have two tags with the same name!) There is "Noise" in Music Production, and in Photography, too. There is "Composition" in Music, in Design, and in Photography. What can I do, name the tags "Composition Music", "Composition Photography"? No, I won't, because that will make me loose a lot of time. I need nested notebooks in unlimited levels, or at least five levels, or ten. OR: The ability to color-code tags, so that I can have two or three "Composition" tags (one red for Photography, one blue for Design, ...) I hope you can understand what I mean... There are people who just need a Notebook for Math, one for Geography, one for Chemistry... But there are many other people who need deeper, much deeper levels of Organization. Thanks.