Did you know that in addition to Metrorail and Metrobus, SmarTrip® is now accepted on ART-Arlington Transit, City of Fairfax's CUE bus, City of Alexandria's DASH bus, DC Circulator, PRTC-OmniRide, Fairfax Connector, Loudoun County Transit, Montgomery County's Ride On bus, and Prince George's County The Bus?
You can buy a SmarTrip® card at any Metro station, add value, and pay by credit card. Be sure to register your new card (online at www.wmata.com). In case it's lost of stolen, you can transfer the value from your old card to a new card for $5. (I guess that's why it's called a SmarTrip® card.)