More seriously, we could scan backups. Or we could live in the Matrix, not as meatbags plugged through the neck, but as programs –which could be backed up as well. (Don't ask me who gets to be root.)
It's funny, because Eli was making a moral argument, but I was not, yet that seems to be the default argument against immortality. I think you last question is actually close to what I was striking at - who is it that's immortal? What does it mean to be a consciousness freed from its humanity? I honestly am not sure that many people would end up being happy in such an arrangement, or necessarily actually survive in any sense as "themselves" for very long, despite the persistence of a body or simulant or whatever.
Improving truck-exterior safety standards: deformable impact points, robot drivers. Combine that with environmental improvements - fewer places to get squished between a truck and arbitrary railings, say. And add medical improvements to the point where you'd have to splat a brain to get a sure kill. Safety standards that require a Culture-style life-support collar on all trucks.
All engineering. It's not good against infinite time, but it ought to make traffic fatalities rare and remarkable.
We should be able to do digital backups of a brain within the next century. If we can attach robotics directly to the spinal column and regrow dead / damaged neurons with stem cells, we can also put people in a literal brain in a jar robot, which would hopefully have the brain effectively reinforced (or better yet, just be a brain in a jar in a secure vault remote controlling an avatar robot).
