Social engineering uses this a lot. It's rare and catches people of guard when a stranger strikes up a conversation and positioning yourself as friendly and attentive about listening and putting the emphasis on the stranger and not yourself can really open a lot of doors. Compliments, reiterating the persons information but leaving it open ended allowing them room to elaborate, etc. People love talking about themselves and they love people that make it easy for them to do.

If you haven't already read Dale Carnigie's "How to win friends and influence people" that book literally changed the way I communicate with people.