Ray Kurzweil is one of the more interesting people i've ever become familiar with. He's got a portfolio of careers and is pretty hard to classify, but definitely a "futurist," someone seen as an authority on technology's impact on the future. And he's been right in the past, to the tune of getting very rich from his predictions.
His next prediction is that human intelligence will be surpassed by machines, and that this will happen in our lifetime (20-30 years). I actually agree with him.
Here's an article on him in this months' Wired, absolutely FASCINATING.
Also, here's a talk that he gave at the famous TED conference on accelerating technology.