I personally am not a big fan of tags, because it's yet another step I have to take when I clip something, and I have to further stop and think about every possible tag I might need for an item. I don't like searching for tags knowing that if there is some item I forgot to tag or mis-tagged, it's not going to show up. It means I'm never quite sure if I've collected all my data. Thus folders are a better metaphor for me - I know exactly where an item is because it is stored with groups of related items. It seems like adding folders for notebooks would be such an easy thing to do -- much like iTunes and iPhoto added folders for playlists and albums. My current Notebook list is just getting too long, so while Evernote is such a fantastic solution for me, if this list becomes too long and unmanageable, it's just going to add more chaos rather than clarity. So I think folders are an overdue and crucial feature. Honestly, a notebook IS just a folder -- I'm not even sure why they're called notebooks. It's a collected group of items.