As you know, it is possible to create ad-ins for OneNote which extend the functionality in the core product. Here ae a few that I use:
OneNote Notebook Cleaner – clean up your OneNote notebook before sending it out to finicky people (is that how you spell finicky? I’ve never actually written that word down before)
Template Manager for OneNote 2007 – quickly apply default or custom templates across an entire section or notebook
OneNote Printout Manager – Some advanced printing features for OneNote
OneNote 2007 Word Count – for all you writers who use OneNote, this counts the number of words on the page (it’s much faster than doing it the old fashioned way, i assure you).
Please share any others you know about with us.