One of my Copenhagen team points to christiania bikes as a possible way of meeting our transport needs when we visit this spring:

Christiania bikes was, as the name suggests, developed in car-free Christiania, Copenhagen. Bicycle trailers, an early product, were followed on the market in 1984 by the first CA-Bike. The bikes were developed in dialogue with the consumers, and safety, quality and durability became the hallmarks of the design. Outside Christiania notice was taken of these solid environmental bikes, which are now exported around the world.