> Assume you create new google doc, and as you begin typing, in a small window/pane/pop-up, relevant information is displayed based on the context of what you are typing with subtle highlighting. As you typed out "San Francisco's population" that phrase would highlight and the context indicator would display that number.

I've been thinking along the same lines, but for a study prosthetic. Imagine a head-mounted camera that OCRs as you read. So, when you read "Navier-Stokes" there's side-bar with everything that you know about Navier-Stokes, equations, code samples, etc.