If the weather is nice and you are comfortable on a bicycle, I would consider getting a citibike pass rather than (or in addition to) a metrocard. It's a faster, cheaper, more exhilarating, and obviously more scenic way to get around the city. Since the program came into being, my subway use is down well over 90%, as I use the subway now only in inclement weather or when making a rare trip above 59th Street).