When I was a kid, my parents volunteered to help run a session of a stop smoking program. Hence I attended the sessions partly when sitting was not available or whatever.
I remember that there was a slide show showing pictures of the effects of smoking. These pics were real life, large screen and detailed. I can't say if these images had any part in my life decision to never smoke, but they may have.
BTW if you want to know what program my parents were helping with here's the link. It has a very good success rate, and maybe there's a TFP reader out there who would like to know a bit more about it. (I don't know if they still show the slides)
http://www.thebreathefreeplan.org/index.htm