Launched in July of last year, the system is being run by ATAC, the transit agency that runs the buses and metro in Rome, and its its fare system works much like the Velib system, being free to subscribers for the first half hour then charging 1 Euro for 30 mins after. Stations are mostly clustered in the Centro Storico (Historic Center) of Rome, though there are a few around La Sapienza University and in Ostia Antica along the coast. On the Google map for the stations, you can even click on each station to see how many bikes are available at any given time.
The bikes are of a more sturdy and conventional design like most Dutch bikes as opposed to the aerodynamic Velib. Each has a rack in back and a basket in front, making them pretty convenient to take a few items. However this stolid design isn't dissuading the ever fashionable Italians from riding them or riding bikes of their own. The bikes I saw Rome, most of them very new, were ridden by ordinary looking Romans, dressed in street clothes or women in their necessary high heels. It seems the culture of bicycling is being seen to be just a normal part of life, even for the Romans.
Two years ago when I lived in Rome, I would not have dared ridden a bike in this city, so the transformation, albeit still very small, is remarkable. Judging by the experience of so many cities such as in Paris, New York and Copenhagen, where bicycling had for so long been seen as ridiculous or dangerous concept, but is now embraced proudly as part of the city's life, I think it's an encouraging sign to see such growth in such a short time.