What's interesting about Twitter and the influencers that someone follows - like, say, Shaquille O'Neal - is that they see someone who is using the exact same tools that they have access to, and I think that inspires this hope to be able to really engage with someone like him.

There's an entire universe in every single tweet, and it all really depends on the content as far as how it's going to spread.

The idea of Twitter started with me working in dispatch since I was 15 years old, where taxi cabs or firetrucks would broadcast where they were and what they were doing.

It's a matter of invitations versus context. Twitter is really good at providing context, like, I''m having coffee at Third Rail Coffee.' Foursquare is about invitations to places. In this respect Foursquare has started to replace Yelp for me.

My goal is to simplify complexity.

IM is interesting because you look at your buddy list and, at a glance, see what your friends are listening to, what they're working on, what they're doing. The problem was that you were bound to the computer keyboard.

It's really complex to make something simple.