If you ride on the sidewalk, remember to act like a pedestrian. In fact, it's best if you walk. If you ride, though, make sure you're riding at a pedestrian-appropriate speed, and likewise cross only with the light, and stop and look both ways before entering the crosswalk, The last thing in the world that a car driver will expect is for a bike to come flying off the sidewalk into his/her path. They will scan the sidewalk for potential 3-4 mph walkers, but not far enough to account for 15 mph bikers.