I just saw on John's blog that he posted another powertoy see what he has to say:

One request I saw on our newsgroup was a customer who had thousands of TXT files which he wanted to import into OneNote. He had apparently used Notepad for years to store data on his hard drive. Fair enough. But now he wanted to migrate to OneNote and was stuck. The only solution he had was to open them one at a time and copy and paste into OneNote. Clearly not ideal. Another person wanted to see some sample code to simply add some text to a page in OneNote.

I decided to write another powertoy to help both of these users. It will allow you to navigate to a folder on the hard drive and import all the TXT files in it to OneNote. It will create a new section with the name of the folder on the hard drive as the section name. And here I hit a snag. I never really liked the behavior of putting all new information into Unfiled Notes by default. While it makes sense most of the time, in this case I really saw a need to control where the imported text files would go. I decided to implement a tree control to let the user choose which notebook the files would be imported. So now you can choose into which notebook you want the imported files to go. And the second fellow who wanted to see the code for this can download the source.

Looks like John is doing powertoys for hire : )  In all seriousness this is super cool, check it out:  Customer feedback results in another powertoy.