Signal surfing: the act of making your way across NYC (or any city w/grid system), plotting your course based upon the traffic signals that happen to go your way. For example, you gradually make your way in a North Eastwardly direction, but the exact turns and street-crossings are determined solely by which lights turn green at the moment you arrive on the corner. Can give the signal-surfer a feeling of serendipity, as if they're floating on the wind or riding on waves.
