I've had a similar idea for a while. It involves reconstructing people from the memories of those who knew them, like Kaj_Sotala describes. So, for instance, my maternal grandfather died a few years ago. But if a bunch of us who knew him lived into a future where our memories of him could be scanned and analyzed, a copy of him could be built that we would find indistinguishable from the original as far as those of us who remember him are concerned. I thought it might be useful from a comfort standpoint.