Is this more life immitating science fiction? E-mail from the grave? Microsoft seeks patent on 'immortal computing' Are estate planners now going to have to start moving into space previously only reserved for futurists and scifi authors? Hrm.
What would you have to say to your progeny many generations removed? Don't we have enough trouble communicating with our own teenagers just one generation removed? Heh.
One of the not-so-secret societies that I belong to has a list of required membership essays to be written over the course of years of membership. One of those is the opposite of what immortal computing enables; it's an imaginary letter to you from a great-grandchild in the future telling you what life is like then to get your perspective about our prospects in the future as a culture and a nation... I think I'll propose a new addition to this of essays: a open letter to your descendants 500 years hence.