I had this idea in the 1990s when it crossed my mind to send an email to my brother, who had died in the 1980s. The idea grew to the point where I contacted an expert in AI at the time to ask him: "Is it possible to build an AI based on a profile of a dead person--an avatar of that person--who would interact with friends and family in a way that mimicked the actual person?" Long question, I know. The answer at the time was "No." A pretty short answer. But I think we might have reached that point. Though it would be weird for me to receive an email from my dead brother, reminding me about the $400 I owe him.