Chris Pratley recently mentioned various ideas for OneNote Power Toys. Personally, I'd really like to see:
It's unfortunate that the hardest part about all of the Power Toys I've heard mentioned isn't the actual import of the final content into OneNote -- it's generally interfacing with the external application: Outlook, Internet Explorer, or Windows for the Print Driver, etc.
Nonetheless, we've been working on ways to make it easier to use and develop OneNote power toys. David on our PM team has been working recently on a single page of add-in's that will be available off of the Office site that will provide links to all the various power toys that you can install with the SP. (For example, I suspect you'll be seeing Omar's excellent Outlook2OneNote add-there. :) And I've been working on a nicely abstracted managed interface to our COM components that feels more like an Object Model. (It's not quite ready for release, but if you're anxious to try it out -- drop me an email, and I'll send you the source.)
It's great to see people thinking about OneNote PowerToys -- one of the best moments in the life of any developer is seeing people use your programs in ways you'd never have imagined.