I loved OneNote - did everything in it, used my tabletPC to the max, wrote notes all the time with the keyboard and the pen, recorded meetings - fab.

then I went off it.

It just got too hard to find stuff, remember where I put it, search for it etc.  I do like having a bit of structure to the sections and pages but after a while there was so much stuff in my OneNote notebook, I just couldn't organise it.  It was really painful to move pages about - select page, move to section etc. I ended up feeling out of control and also the tablet aspect of my old tablet started to go wonky and wouldn't calibrate.  Actually the calibrate dot was not reachable even when I was right at the edge of the screen.  OneNote got stressful.

So I stopped.

Now with OneNote 12, I'm back.  I have rediscovered my first love of OneNote since we added the notebook feature.  You can drag and drop pages onto other sections and look at all your notebooks down the left hand side:

 

Also you get the expanded version if you click the "all notebooks" at the bottom.  I love the use of these expandable panes in OneNote and in Outlook as well.
In Outlook12 if you click on the little chevrons in the folder pane and the to-do bar, you get little bars on the right and left giving you summary info but leaving you the rest of the screen to do your email.  It reminds me of the visual studio approach of putting panes out of the way when you don't need them.

So I am back with OneNote, doing all my planning for launch with it.  It is so great not to have to write everything in a structured Word document when I am at the ideas stage.  With the fantastic task integration with Outlook 12 it is very easy to brain dump in OneNote but flag for follow up later.  We are very "file" oriented in IT.  A concept which doesn't really make much sense to non teckies.  OneNote doesn't have a save button, you just write your thoughts there and thats it.  Now that I can organise it, it acts like a salve on an otherwise boggled brain - like a thought extension space for the mind.  The task integration means that transition from random thought to more structured activity is smoother and means I tend to let myself think more freely without feeling guilty that I should be "doing" something.  Even Einstein came up with relativity while idly dreaming about riding on a light wave.  Maybe OneNote will encourage us all to spend more time being random and more innovative.

There are loads of great innovations in OneNote 12 but for me it was this one killer feature that has got me back loving it and keen to explore the rest of the product. 
The shared workbook stuff looks very cool too so I'll try that next and let you know how I get on.

My mate Owen Braun writes a very interesting blog on OneNote and I think this post was very good for explaining what I mean about OneNote transcending "document" thinking.
He also chose the exact same msdn blog format and colour scheme as me which is a weird coincidence..