I can't see this being useful at all.
The beauty of post-it notes is that they are simple and temporary. If you start adding "clever" stuff to it, they lose that simplicity. Not to mention you would have to remember to use their special pen/pad for the computer to detect it.
Also if you are so disorganised you keep meetings you have planned or other important information on post-it notes then I don't think this would help you.