I don't think of Twitter as a social network. I think of it as a messaging system that has a lot of social components to it.

What if the New York Times gave out free, cheap Kindles to everyone and said this is how we're doing it now. You know? Maybe that's a way to go. The technology gets cheaper and cheaper, and at some point it has to be cheaper than all these trucks and all this gas, to just say, let's give away a Kindle to everyone.

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

There are a lot of sources of information out there, so why don't you curate for yourself a list, like a real timeline of information, like the New York Times, or JetBlue, or your friends, or this comedian, or this guy who pretends to be a cat, or whatever it is, whatever entertains you, whatever you find useful.

The most rewarding thing for me has been this affirmation for me that people are basically good and smart, and if you give them a simple tool that allows them to exhibit that behavior, they'll prove it to you every single day.

Even the simplest tools can empower people to do great things.

Doing startups is all about making mistakes.