So the whole thing becomes a very different kind of working. Working prototypes of such touch pads exist and are expected to enter the market in the fall. The next step may be integrating a lightweight display with this touch surface technology, uniting all three original components. You'll have very high resolution, so you can have lots of small type on a small piece of paper. You'll have a stack of papers and they can update easily.
Paper is thin, flexible and lightweight.
Display glasses could be part of the future of mobile computing. Display glasses, too, are already a reality, though often as part of wearable computers, which themselves are rare. According to Winograd, they probably won't become popular in the short term. You'll be carrying your cell phone anyway. If you're talking long term, your cell phone will be replaced by something like a hearing aid.