Given the stereotype of single hackers, I'm not sure if this qualifies as a "practical solution that can be built now" -- but my plan for continuing my presence in the world (both online and offline) involves having kids. :-)
Even if I could live forever, I hope that I wouldn't continue to hold an unchanging view of the world. I know I look at things differently now than I did 10 years ago -- why would I want my kids (if and when I have any) to adopt the views that I have now, when I probably won't hold those precise views ten years later?
My girlfriends pops was telling me he wants a myspace for dead people.
Like a repository of videos left to certain people in the family, pictures, a comment section, and then have other little features like getting a text or email every year when its their birthday or the day they died.
Of course this would be all done by the person, while they are still living, in preparation or anticipation of their death.
As an approximation, you could use a social approach where people try to imitate Einstein as closely as possible along with some way of evaluating which imitations are more successful than others.
In his book Sun of Suns, Karl Schroeder discusses an entity who is neither a physical person nor an AI; he's the product of a "game church", where people join up and take shifts beating out a heartbeat, or sending nerve signals to other people in response to signals they receive, and an intelligent entity emerges from that, despite the fact that none of the people are making decisions for that entity. Sort of a Chinese room thing.
