Soon (or perhaps already), Washington DC will have its own Euro-style bike sharing program, the first of its kind in the US. SmartBike DC will provide racks of bikes, conveniently located throughout the city. Cyclists will be able to rent bikes for one-way trips by taking them from one rack and leaving them at another. The rental process is completely automated, with an electronic card-swipe system. Similar systems have been operating for awhile in European cities such as Paris and Barcelona.
Originally scheduled for an early spring launch, SmartBike DC has received a lot of press already, including feature articles in the New York Times and Washington Post.
Though on a smaller scale and not automated, ShareBike in Roanoke provides a similar service, with downtown locations convenient to the Hotel Roanoke and Roanoke River Greenway.
For ongoing information about bike sharing programs, see the Bike-Sharing Blog by MetroBike LLC.