In Germany, the DB Call-a-bikes bikes don't have a locking station and cost only €1000 to initially build.

I think this is a much smarter system due to lower starting costs and lower overhead.

http://en.wikipedia.org/wiki/Call_a_Bike

edit: that wikipage is wrong as the bikes don't need to be locked to a fixed object. They usually just stand around with a rear-wheel lock.

more info:

http://www.eltis.org/index.php?id=13&study_id=198
http://www.callabike-interaktiv.de