I think of Twitter as a messaging system that you didn't know you needed until you had it. Think about when cell phones first started coming out. People said, "Why would I carry my phone around?" And now you'll drive back to your house thirty miles if you forget your cell phone.

We didn't have anything before Twitter that allowed a group of people roaming around a city to communicate instantly, in real time, and in a coordinated way, in a group.

We can break news really fast. When an earthquake happens, there are people Twittering about it.

Positive culture comes from being mindful, and respecting your coworkers, and being empathetic.

The reason I really started running was for meditative purposes. I would pick some problem to have in my head while running.

When you think of a social network, you have these two-way interactions: "Are you my friend? Yes? No? Yes?" Like LinkedIn, it's business oriented, but it's all about establishing connections. You connect to me through my other connections, and that sort of thing, and you sort of define who your friends are. Twitter doesn't have that.

The two things I use the most are the MacBook Air and my iPhone. Those are my two most-used gadgets that are dented, scratched and smashed.