I have been using a similar System for years (~7). For hardware I've used a ThinkPad Transnote, Cross CrossPad, Seiko SmartPad and Seiko InkLink. You will recall, the Transnote was a laptop with a tablet digitizer on the side that held a paper notebook on top. You'd write your note with a special pen on paper, tear the sheet and shove it inside that monograph on algebraic topology you were reading. Of course, you'd get a digitized copy for later perusal. Same idea with the CrossPad which was the same hardware and software minus the laptop. The CrossPad tablet had it's own memory that allowed you to save the digitized info and then transfer it to your computer. The Seiko SmartPad was basically the same idea and the same type of digitizer, albeit a smaller format, but it needed your Palm or WM device connected to it. Later Seiko introduced the InkLink which is, I think, the same type of device in the, MIT prototype. It is basically an ultrasound sensor that clips on to a regular paper writing tablet and the pen has an ultrasound emitter. All the Seiko devices came with Software that would let you use either device on a Palmtop or on a Windows PC. All of the IBM, Cross, and Seiko devices came with software that allowed you to do most of what the MIT device does. One important difference that is not highlighted in the clip is that by including an RFID chip in the handwritten note you are later able to pinpoint the physical location of the note.