John Guin a new Test Lead on our team wrote up this great tool which will take messages from Outlook and create a new OneNote note for them. Here is the description:
This addin adds the capability of sending yourself email with a certain keyword in the subject and having Outlook automatically create a new page in OneNote's Unfiled Notes section when that mail item arrives. Outlook then deletes the email. It also allows power users to set the filter used for incoming mail items to trigger the code. It provides no UI for the user: "it just works."
What more can you ask for? You can download the setup.exe as well as the source code all over @ the Code Project: Outlook To OneNote AddIn. Nice work John!!
Update @ 2/9/2007 2:39 AM: I just heard from John that the Code Project strips out apps which have setup.exe in their name. I have posted the setup files here: OutlookToOneNoteAddinSetup.zip. That should work for you now!