Having kids has been a fantastic thing for me. It's meant that I'm a little more balanced. In my twenties I worked massively, hardly took vacation at all. Now, I, with the help of my wife, I'm always making sure I've got a good balance of how I spend my time.

In most of these things our foundation is a co-funder, so I can say that a polio or an HIV vaccine, that I'm putting our resources behind it in a very big way and the U.S. government would be the best partner for those efforts.

There is no doubt PC prices will be coming down.

You have to be willing to see that sometimes the governments of these poor countries don't come through. You have to think about that as a constraint. How do you help them be better? How do you come up with things that actually work, even in those tough situations.

Taking a look back, one big reqret is, I left Harvard with no real awareness of the awful inequities in the world. The appalling disparities of health and wealth and opportunity that condemned millions of people to the lives of despair. I learned a lot here at Harvard about new ideas and economics, and politics. I got great exposure to the advances being made in the sciences. But humanities greatest advances are not in its discoveries, but in how those discoveries are applied to reduce inequity.

I considered law and math. My Dad was a lawyer. I think though I would have ended up in physics if I didn't end up in computer science.

The Internet is the easiest thing to get into. To be an Internet retailer, you just get that URL.