Capital Bikeshare launched the largest bike share program in the US today with 13 stations in Arlington and 36 in DC.  Membership is required but can be purchased for a day, a month or a year.  Once you’re a member, you will get the first 30 minutes of each trip free and pay a trip fee for any time beyond that.  Visit the Capital Bikeshare website for more information, fees, and a station map.