http://bikes.oobrien.com/ has real-time bikeshare maps for many cities around the world. A few cities, like Paris, have stopped sharing data for some reason. Most of the others, including Montreal and Washington, seem to be okay sharing their station data. The maps also list how many stations are empty and how many are full, as well as circling them on the map. If you click on a station, you get a graph of how many bikes have been at that station in the last 24 hours.