A: Vinod Khosla has a good size fund I've invested in. I put over $20 million into that particular fund. I get to talk with the entrepreneurs he's funding and learn from them. TerraPower, a spin out of Nathan Myhrvold's Intellectual Ventures, is pursuing nuclear power design. If everything worked it would provide cheap energy with no CO2 emission. We need hundreds and hundreds of entrepreneurs to try new approaches... all we need is an approach that works.

Q: Looking at health efforts in Africa, such as HIV prevention and treatment, are you concerned about the Ugandan anti-homosexuality bill, and have you spoken to anyone there about it?

A: The spread of AIDS is a huge problem and obviously we're very involved. I talk in my letter about the great success with this male circumcision effort, and preventative drug trials. There's a tendency to think in the U.S. just because a law says something that it's a big deal. In Africa if you want to talk about how to save lives, it's not just laws that count. There's a stigma no matter what that law says, for sex workers, men having sex with men, that's always been a problem for AIDS. It relates to groups that aren't that visible. AIDS itself is subject to incredible stigma. Open involvement is a helpful thing. I wouldn't overly focus on that. In terms of how many people are dying in Africa, it's not about the law on the books; it's about getting the message out and the new tools.

Q: We've seen a huge outpouring of support for Haiti -- do you think the foundation will play a bigger role in relief aid, or what role do you think the foundation can play there?

A: If you go back and look when there's been an emergency we're always giving gifts very rapidly to some key partners... A lot of giving we do is way before the crisis takes place. A lot of the big impact comes from the gifts that are given before. Haiti was the poorest country in the region before this. I've been down several times. There's a lot to be done there. I hope this is not just a one time thing. The generosity is great to see - it's almost half of American families. It's great to see the response that's taking place. Haiti was a place that is going to need long-term investment, and so the foundation's been involved.

Q: The foundation has grown to almost 1,000 people and is moving into a $500 million new campus. How can you ensure that it doesn't become too bureaucratic and top-down in its decision-making so you are encouraging innovation inside the organization?

A: The real innovators are the people we fund and the key to the foundation is to be very open-minded to unusual ideas and approaches. Grand Challenges is an example of that. We open it up to just anybody. When people review those grants they don't even know what fancy title applicants may have. We'll need to use novel approaches to make sure we're not just getting the best work of the top universities, though we expect to see a lot of innovation coming from the universities themselves. For these Grand Challenges research grants we track the grant applications, and what percentage is being granted to developing countries. We actually give them a boost...

We need to keep reinventing ourselves and being smart. My annual letter lets me talk about mistakes. My being out on the Internet will let us know what people think and what they agree or don't agree with.