I was travelling around my country Ecuador, in the highway there's 3 or 4 tolls, so I just stopped in one of it and say a pretty nice and honest "How your doing?" to the lady who was attending the toll. She just answer with a sincere smile in her face. I think you can always do something else for someone just with the correct and nice words. This people work all day in a small cabin and most part of the day they see people but non of them say something kind to them.