How is this type of dropdown used in Amazon called?
It basically permits you to select among a selection list and then it auto submits your selection via jquery and retains it for the rest of the session. In the case of Amazon EC2 you select the country of your server and all the rest of the menus are relative to that country.
If someone can suggest a name for this concept and other notorious examples of sites which use it.
EDIT: language selection is a very common case of this kind of dropdown by the way.