Governments will always play a huge part in solving big problems. They set public policy and are uniquely able to provide the resources to make sure solutions reach everyone who needs them. They also fund basic research, which is a crucial component of the innovation that improves life for everyone.

The future of Windows is to let the computer see, listen and even learn.

In the same way that when the car got going, people thought it would be an electric car, people thought it would be a steam car.

The nuclear approach I'm involved in is called a traveling-wave reactor, which uses waste uranium for fuel. There's a lot of things that have to go right for that dream to come true - many decades of building demo plants, proving the economics are right. But if it does, you could have cheaper energy with no CO2 emissions.

Music, even with these dial-up connections you have to the Internet, is very practical to download.

So on the demand side [for energy], there have been a variety of policies that globally have been way over $50 billion a year of tax credits, raising the price of electricity through things like renewable portfolio standards, so the total amount of money that's gone into sending a price signal to push up demand versus what would happen without it has been gigantic.

Even with cameras being very cheap, one thing that researchers noticed was that you look really bad in a videoconference image because the lighting is bad and you get shadows and things.