I just read this and I agree... I believe that there is a very large problem these days with the general public and the lack of manners and disregard for the fellow person.
Reading through the list has brought a few things to mind... For me I would have to list basic table manners as my biggest pet peeve. My mother drilled these into me a as a child and I am generally shocked at the apparent lack of intstruction these days. Meaning, elbows on the table, chewing with mouths open, speaking with mouths full of food.. these kind of things are never acceptable and I cannot fathom my their mothers / fathers / parental figures never taught them how to behave like civilized humans at the table.
Lateness is another pet peeve of mine, 5 minutes is fine, frustrating but fine, but after that it becomes rude and shows the obvious disrespect that the person in question has for someone's schedule.
Yikes, that was rather preachy wasn't it....