If you went around saying that in a couple of decades we'll have cell-sized, brain-enhancing robots circulating through our bloodstream, or that we'll be able to upload a person's consciousness into a computer, people would probably question your sanity.
But if you say things like that and you're Ray Kurzweil, you get invited to dinner at Bill Gates' house - twice - so he can pick your brain for insights on the future of technology. The Microsoft chairman calls him a "visionary thinker and futurist."
