Many European cities have tried to become bike-friendly, and Paris is among the most successful. They have a very popular loaner bike system where thousands of city bikes are parked in hundreds of racks all over town, which locals use for quick little one-way hops. And bike tour companies are quite popular here. I took a tour one afternoon last month and rolled through slices of town I had yet to see. I loved this section: an open art gallery along a stretch of the Seine (just downstream from Notre-Dame) that has become a people zone — especially in the evening, when there's music, dancing lessons, BBQs, and so on.