[Oct.2012] It started in Paris in 2007 and now all over the place.
This rental bicycle service started in December 2008 in Milan.
The bicycles are yellow in Milan, very Italian.
In Paris they are grey, and in London they are blue, by the way.
You can rent and return them anywhere and use them 24 hours.
It is so convenient that ordinary commuters like this one use it and has become a part of everyday life.
I seem to remember that the original Paris version is being run by a big adverts company, but it seems that in Milan, ATM, a public entity which oversees metros and buses operates the system.