Okay, this is cool. From ReadingMate:

Though reading could be a useful activity for joggers running on a treadmill, the text) is vigorously changing, our eyes must constantly adjust to such changes, which is burdensome. In order to alleviate this difficulty, we developed a infrared-camera-based contents stabilization technique, called “ReadingMate,” by using head-tracking to track the location of the jogger’s head/eyes and relocate the contents on a screen so that the contents appear to be stabilized.

Maybe not the most pragmatic thing ever -- I started thinking of what you could do with a projector on the wall before going "wait... wait, maybe not most useful interface ever to think about implementing in apartment" -- but it's an interesting look about head tracking, which is something I've been thinking about lately.

One thing I became aware of on the 2nd day of dance class (several weeks ago, now) was my habit of horizontally stabilizing my head. This makes sense; I'm more reliant than most on fine-tuned visual input (lipreading, supplementary text). These are mostly still and vertical. Hence, my head is still and vertical, even when the rest of my body is moving -- a habit I'm breaking now in my motion, deliberately. There's still a moment of slight fear when I let my head go out of vertical and spin around: wait! You'll miss something! But I know I've put myself in a situation where there's nothing to miss.

I wonder what I can do to make this more of an environmental factor, a habit of sorts, in the places I'm in. Hanging worksheets/instructions on my wall off-kilter might be a start, so I actually need to lean (with good body alignment -- consciousness!) to read them properly.