This summer brings a new regional bike-sharing system, Metroradruhr, to ten industrial Ruhr valley cities. Started on June 18th in Dortmund, Germany the system has now reached five of the cities. Bikes are now, or soon will be, available in Bochum, Bottrop, Dortmund, Duisburg, Essen, Gelsenkirchen, Hamm, Herne, Mülheim an der Ruhr and Oberhausen. This is not just a series of suburban satellite additions to a larger city system, but a single system connecting nearby cities together. The most similar operation is Italy's Bicincittà, but the cities and stations of Metroradruhr are close enough together to allow bikes to move between cities. World Changing

This article also led me to find a google map on bike sharing locations world wide.