Flying cars are not a very efficient way to move things from one point to another.

Teaching is the human thing, in terms of building the kids' self-confidence, so if we take the broad ways that we want to see society to be better, science can only provide certain pieces of that.

Technology must be implemented as part of a thoughtful, holistic approach to education transformation that includes teacher training, relevant curricula, parental involvement, and programs for children that fill unmet needs for basics like nutrition and health care.

Should there be cameras everywhere in outdoor streets? My personal view is having cameras in inner cities is a very good thing. In the case of London, petty crime has gone down. They catch terrorists because of it. And if something really bad happens, most of the time you can figure out who did it.

In the philanthropy game, you're going for different outcomes: saving childhood lives, having kids grow up - because they don't have malnutrition or disease - that they achieve their full potential. We take for Warren [Buffett] things that, because he's very intelligent about the world but doesn't get to go out in Africa and see what we see, we've taken and say to him where we stand and it's basically a very positive report that his gift has made a phenomenal difference.

Well, no one gives aid to Zimbabwe through the Mugabe government.

Philanthropy, although it's tiny compared to the government, it's 2% of the US economy, which is the largest percentage, other than the Middle East.