We have two other countries, Pakistan and Afghanistan - again it's the instability that is a problem there. So over the next several years, we expect to drive the number of [polio] cases back down to zero because that is likely to be the second disease after smallpox that we completely eradicate.

If you're using first-class land for biofuels, then you're competing with the growing of food. And so you're actually spiking food prices by moving energy production into agriculture.

Most of our competitors were one-product wonders... They would do their one product, but never get their engineering sorted out.

Windows 8 is key to the future, the Surface computer.

The US really has to get out in front. We are the biggest per person, by a substantial amount, greenhouse emitters, and we give the most foreign aid, not per person but in absolute.

In my 20s, I worked very, very hard. I have a much more balanced life now.

As we get robots becoming more sophisticated, I think we should worry sooner rather than later on how much they could take over, but I think it'll mostly be a positive thing. In terms of deadlines it won't be any worse than nuclear weapons.