When I was a collegian, we were told to stand whenever an alumna entered the room as a show of respect. This wasn't a hundred years ago, but it was in the 80's and it was in Atlanta.
How about people who charge into an elevator before letting those who are inside out?
Though it doesn't really qualify as etiquette, I hate, hate, hate when shoppers leave their grocery carts scattered around the store's parking lot. There's a cart corral that will ensure that they don't blow into and damage others' cars (like the Toureg I saw broadsided). It also lets others actually park in empty spots.
Don't even get me started on co-workers who monopolize the network printer, and don't replace the paper.
/rant
I just got Kate Spade's Manners book for Christmas. I'm sure I'll have more to add later.