This was a pretty pleasant surprise. I was using my Tablet PC in Portrait mode which I don't often do, and then I clicked the "Dock to Desktop" button.

And instead of docking to the right side of my screen as it normally does when my computer is in a landscape orientation, it docked to the bottom of my screen. That's good that the "Dock to Desktop" feature took into consideration how my screen was rotated & how to best make use of its available space. It's one of the many things that makes OneNote such great software.