Bicing is Barcelona's version of a city bike share. By paying an annual fee of €47.16, Bicing members get a card they can use to take a bicycle from one of the terminals placed all over the city. The first 30 minutes are included in the fee, but if you exceed that time limit, you'll have to pay 74 cents for every extra half hour, up to two hours.
Don't think your only options for getting around Barcelona are by a crowded tour bus, an expensive private tour or even public transport. Get outside when the weather's just right (which is almost always), see the sights in your own time, and get to know the city close-up. From a government sponsored bike program to various bike rental compaines that offer hourly rates and all day tours around the city, the options are endless. If you're feeling especially adventurous, try one of the segway tours or a bike tour package that not only takes you around the city but some include stops at restaurants for delicious tapas.