Could you please say where I can find the layers for Australia?
I need just Northern Territory State
I need basic layers like buildings, roads and others in shape format apart from the cloudmade.
You can download it in shapefile format from the geofabrik but I don't know about the quality and quantity of data regarding Australia.
It seems you can specifically find Northern Territory boundaries here. You then run an intersection to get data on desired area with that wonderful tool named QGIS. Here is a video tuorial regarding intersection.