The notes feature in Outlook/exchange is secure and accessible through OWA and on my Blackberry/BES.
How can Onenote offer the same functionality as I am looking to switch to Windows Phone 7 which only offers Onenote support?
I'm afraid Mark's answer does not answer your question and the reference to a Zune forum is useless.
OneNote is a fantastic application, by the way, and it compares to Outlook notes as maybe a Rolls Royce does to a Beetle. You'll be entering a whole new world, though ;)
In a nutshell, if you want to use OneNote in combination with Windows Phone 7, you keep master copies of your OneNote notebooks on your SkyDrive (in the cloud). Your phone's OneNote app can then be made to synchronize with these notebooks. If you have
OneNote on your desktop PC, it, too, can synchronize with these same notebooks. Same for your laptop. Etcetera. In this way, you have identical copies of everything everywhere, with the master being on SkyDrive. Note, however, that it is no longer possible
to sync phone and PC over a cable.
I don't know if this makes any sense if you have never worked with OneNote. Ask away if it doesn't.
As to security, I don't know, honestly. How secure is data on SkyDrive? That's how secure your notes will be.
Hope this helps,
Jan Roelof