Vaccination is pretty special because you can do a vaccination campaign anywhere in the world. All you are doing is gathering women from the villages, getting them the vaccines and asking them to go around and find the children.

There's 20 companies that I have investments in - some batteries, some solar-thermal, one big nuclear thing. We need hundreds and hundreds of companies like that, so that in a 20-year time frame we really are starting to change the energy infrastructure.

When making choices, or setting policies about the economy, education or medicine, society is best served by electing people who are particularly hardworking, intelligent and interested in long-term thinking.

When Ford sells a car, a dealer isn't allowed to take out the engine and put a different one in. When a newsstand sells the Washington Post, no one can go to the newsstand and pay them to rip out the classified section and put their own classified section in - if they could, they would do so.

In ninth grade, I came up with a new form of rebellion. I hadn't been getting good grades, but I decided to get all A's without taking a book home. I didn't go to math class, because I knew enough and had read ahead, and I placed within the top 10 people in the nation on an aptitude exam.

I remember thinking quite logically that I didn't want to spoil my children with wealth and so that I would create a foundation, but not knowing exactly what it would focus on.

Driving up the value of the advertising is a big commitment for Microsoft.