I loved couriers. You had this transfer of physical information happening throughout the city and the world. Someone picking up the package, putting it in a bag, going somewhere, taking it out of the bag, giving it to someone else. I thought that was so cool. I wanted to map it, to see that flow on a big screen.

It's really complex to make something simple.

I think Twitter is best when it sparks conversations elsewhere. To use YouTube and Facebook and all the tools we have available to us today to respond and also promote and answer and engage is awesome.

Twitter was around communication and visualizing what was happening in the world in real-time. Square was allowing everyone to accept the form of payment people have in their pocket today, which is a credit card.

Pick a movement, pick a revolution and join it.

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.

Make every detail perfect and limit the number of details to perfect.