There's a great article in the New York Times about the boom in bike share programmes, with focus on Bicing in Barcelona.
From the article:
"In increasingly green-conscious Europe, there are said to be only two kinds of mayors: those who have a bicycle-sharing program and those who want one.
Over the last several years, the programs have sprung up and taken off in dozens of cities, on a scale no one had thought possible and in places where bicycling had never been popular."
"Officials in Lyon, one of the first cities to institute a large technology-driven bike program, estimate that bike-sharing has eliminated tons of pollutants since its inception in 2005. But more than that, they say, it has changed the face of the city.
“The critical mass of bikes on the road has pacified traffic,” said Gilles Vesco, vice mayor in charge of the program in Lyon. “Now, the street belongs to everybody and needs to be better shared. It has become a more convivial public space.”