I try to be a "good neighbor" in sharing bike/pedestrian paths. I always slow down when I see others ahead and can usually pass without issue with a simple "on left" spoken in slightly louder than conversational tone. However, I am considering buying a cheap bell for use in situations where walkers and/or roller bladers are wearing headphones and are seemingly oblivious to everyone but themselves. I can't get their attention with a slightly raised voice, and, particularly with bladers, their leg strokes utilize the entire path so not safe to try to pass without their awareness. Maybe getting dring-dringed would be better than scream-screamed?