Berlin is one of my favorite cities in the world. I feel like the energy is very youthful. It has such an important history, including its recent history of unification.

If the original Facebook was the first five minutes [of a conversation] and the stream was the next 15, what I want to show you today is the rest-the next few hours of a deep engaging conversation.

Some of the best ideas throughout the company's evolution have been from places all throughout the company whether it's an engineer or someone on the customer support team. Just different areas around the company.

In a world that's changing so quickly, you're guaranteed to fail if you don't take any risks.

We want Facebook to be one of the best places people can go to learn how to build stuff.

No one has done a study on this, as far as I can tell, but I think Facebook might be the first place where a large number of people have come out. We didn't create that - society was generally ready for that. I think this is just part of the general trend that we talked about, about society being more open, and I think that's good.

Facebook is inherently viral.