You know the sort of thing. Those littlle mannerisms that drive you nuts. For me its the silly little pretend cough emanating from someone when I light up a fag several metres away from them. It usually comes from a middle aged, middle classed female with lips pursed like a chicken's bottom, and generally means "I don't actually have a chest problem but I want you to know that I know that you're smoking and I don't approve". So what little foibles drive you to homicidal rage??