Barcelona public environmental transport.

I’m sure it sounds better in Spanish or Catalan; I’m reading the translated web site). Here’s how it works: Once you register with the service (you have to be a resident of Barcelona, and it costs 24 euros) and get your swipe card, you can use any one of 1,500 Bicing bikes around the city. The first 30 minutes of every trip are free, and you can return your bike to any Bicing location around the city (there are at least 100). Every half-hour over the initial free half-hour is 30 eurocents.You can keep any one bike for up to two hours, and you can always return a bike, run your errand, and grab another for no charge. The bikes seem to be very well-maintained, and everyone uses them—old people, little kids, hipsters on cell phones, everyone.