A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
According to this: http://answers.microsoft.com/en-us/office/forum/office_2013_release-onenote/onenote-2013-tasks-in-outlook/8e3a2f59-fcb3-4bcf-ad44-a9518fec46c4
Same steps for outlook 2007 should work in 2013 as well. I did not check though.