Professor Marvin Minsky from MIT is not only one of the smartest people alive, he also has a great sense of humour. I remember him standing in the back of the room at various Medialab events, in his classic khaki west with many many pockets, dryly throwing out sarcastic to-the-point comments on what was happening. He once remarked that he encounters aproximately one intelligent person online per year and I suspect that he finds 99.9% of what's going on in the world to be to dumb to even comment on. And speaking of Marvin, Steven Johnson reports from this years TED conference;
On a lighter note, Marvin Minsky walked through a couple of half-serious ideas for combating the population explosion -- ideas that he seemed a little surprised that no one was yet exploring. My favorite: make people smaller! If we're going to be able to genetically engineer ourselves, maybe we should work on shrinking ourselves down so the planet can fit more of us. As Minsky pointed out, a 6-inch person is a thousand times smaller, volume-wise, than a normal-sized one. Of course, he didn't get into the crucial corollary problem we'd have to solve if we pulled this off -- namely, Giant Killer Squirrels -- but I'm sure with time we could solve that one too.

[Just had a thought; Would also be really handy when we're moving into serious deep-space exploration. Send a big team of microdudes in a spaceship the size of a vacuum cleaner...]