Ilya created the OneNote OM Spy tool back in 2007. Here it is updated for OneNote 2010. It works much like the original, so I don’t think I need to post a new image or anything like that. There is one change - you can choose which schema you want to use with the dropdown along the top of the window:
As usual, the download link is below my signature at the end of this entry. And the documentation for the schema for 2010 is here.
(For what it is worth, I never understood why it was called OMSpy - the "m" is a mystery to me).
Questions, comments, concerns and criticisms always welcome,