People who are using it to sell things on Craigslist to holding garage sales - campaigns - the Obama campaign and the Romney campaign both used Square to raise funds.
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.
The Web provides a very easy way to immediately grasp what's going on. It really offers the transparency, so you can see, especially with the search engine, how people are using Twitter at one glance. The phone doesn't allow for that.
TweetDeck is a very interesting client, because it presents a view that no other client in the world presents, which is this multicolumn, massive amounts of information in one pane. And people really, really enjoy that.
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.
I fell in love with flora of all types, especially ferns. Loved the sparse structure and repetition of shape - almost fractal.