Considering the Unicorno in Florence?
A VT member wrote the following comment about visiting Florence:
Free bikes by fgfi
Firenze Parcheggi, the public garage authority, has set up bike stands all over Florence providing free bikes from 8 am to 7.30 pm, on a daily basis! You can return bikes to any of the sites, which include the train station, Piazza Strozzi, Via della Ninna near the San Lorenzo Market, Palazzo Vecchio and large public parking lots.
For more info you can visit the website which offers also an english version.