Been using a bell on my bike for about four years now and its great. People appreciate being warned and usually move politely out of the way. Its a bit like being Moses and parting the sea
However, don't use a bell when horses are around, that freaks them out.
My friends initially took the p*** but when walkers moved with a few ding-dings they saw the light. They weigh a few grams, take up little handlebar room and so much better than shouting at somebody.
However, whichever method you use, you will still encounter deaf people, headphones and those who don't want to move.........
Go on get one!