Land on Mars, a round-trip ticket - half a million dollars. It can be done.

Facebook is quite entrenched and has a network effect. It's hard to break into a network once it's formed.

And we need things in life that are exciting and inspiring. It can't just be about solving some awful problem. There have to be reasons to get up in the morning.

Many things are improbable, only a few are impossible.

Great companies are built on great products.

A Prius is not a true hybrid, really. The current Prius is, like, 2 percent electric. It's a gasoline car with slightly better mileage.

Entrepreneurship is like eating glass and walking on hot coals at the same time