So biking in this city is an experience.
Firstly, everyone goes at a leisurely pace. In the states, bikers are either excercise fanatics or hippies, so they take it pretty seriously. Here, everyone bikes to get everywhere. So people just go a whatever pace they like (and there are only single-speed bikes for the most part) and they'll get there when they get there.
Secondly, there doesn't seem to be any right-of-way rules with cars. If the car is going, you'd better stop. If you have a big group of people, maybe the car will stop for you. Or maybe not.
Thirdly, people carry everything with them on their bike. Friends often sit sideways on the rack behind the seat. People seem to collect large amounts of cardboard and carry it in a cart behind them that is stacked 6 feet tall. Today, I saw a man carrying three rice cookers and his grocery shopping strapped to the back rack or in front of the handlebars. And sometimes, there are little chairs in the pull-carts for children or women to ride in.
Oh, and absolutely no helmets.