Vélib (combining vélo, or bicycle, with libre, or free) is a city program that allows registered subscribers to rent a bike for free at automated rental stations like this. As long as the bike is returned to another rental station within 30 minutes, there is no cost.
Using a series of Vélib bicycles, it is possible to cover large distances within Paris without spending anything. I love this idea.
Bike sharing has continued to spread in other major cities around the world in the years since I took this photo - and my first experience actually using such services would come in July 2014, in London.