Looking for ways to travel green?

Well, the good news is that European-style bike-rental programs are starting to appear across the United States.

Right now, two U.S. cities are following in the footsteps of cities like Paris and Barcelona, which have popular city-wide bike-rental programs.

Washington DC’s program, SmartBike, currently has 10 stations around the city. For $40 a year, members get unlimited access to the bikes, which can be rented for three-hour periods.

Denver, Colorado, has a program called B-cycle, in which riders can rent bikes for unlimited amounts of time. These bikes are loaded with gizmos that record how far you’ve traveled, how many calories you’ve burned—and of course let’s not forget the carbon offset.

And if you’re in a city that doesn’t have a bike-sharing program, just check the Web site RentaBikeNow.com. It allows users to reserve bikes ahead of time from local shops around the country—whether it’s for an afternoon, or an entire week.

For more information, don’t miss our Hiking & Biking section.