I encourage all people who enjoy seeing lots of bikes on the streets to visit Florence, Italy. When you are there buy bike for 50 euros and sell it for the same amount when you leave. There are literally hordes of bikes parked everywhere. In this city crowded with tourists you can safely ride a bike though dense crowd, and leave your bike anywhere next to fifty other already parked there.

Of course bikes do get stolen as everywhere else so locks are obligatory, but herds work for bikes as well as they work for herbivores.