Thanks. This is great.

I'll be running this on all my systems forever.
If only one could have the same for the Explorer toolbar buttons, the start button, the tray. A universal auto-hide for buttons and other UI elements - the minimalist's dream.
Can you make it not restore the window icon along with the buttons when hovering? It sometimes shows them, sometimes doesn't. I'd like to have an INI option for the behavior.
Can you restore the icon in the toolbar when hovering, either on the button or in toolbar area?
Can you make it work when hovering on background windows?
Can you blank out the window borders - make them transparent - in a similar fashion? If not blank out, then fill with some solid color. It would be neat to have borderless windows that only appear when hovering.
Can you blank out the right side of the Explorer statusbar (which, I just noticed, in Explorer menu is "Status Bar" which seems inconsistent with the way "Taskbar" is written), the part that has the unnecessary My Computer/Internet or simply fill it with a solid rectangle and remove it when hovering? The user would have to match the color and perhaps the height to the visual style - unless there are system variables for those that you can use.
Can you use a system variable to find out the actual height of the titlebar instead of the fixed value, 22? I use a larger title bar and it ony shows when I'm at the top 22.
Can you remove the empty space occupied by the invisible icon in front of the taskbar buttons?
I'd prefer it to ask nothing upon startup and default to hide buttons and have no tray icon.
Bug: Right clicking taskbar button doesn't bring up the menu (though sometimes it does).
Bug: Buttons not removed on command line window.
Bug-like behavior (due to implementation, if I'm correct): it keeps blinking with TeraCopy and 7-Zip, that update the % done in the titlebar.