Bikeshares are popping up across North America, with Montreal's Bixi being the first. Here's a short video on the success of Minneapolis's system called Nice Ride (purchased from Bixi), which is now one year old.
One thing to keep in mind is that bikeshares work best in cities with significant amounts of bike infrastructure (bike lanes, separated on-road bike paths, pathways, etc).
http://www.grist.org/biking/2011-08-01-bikeshare-makes-for-a-nice-ride-in-minneapolis-video
cheers,
Beth