Standard issue in Japan, at least on the bigger cars and trucks. I can see the need, at least one would be more certain of the spacial situation while parallel parking. I have seen cars with the same pole but it has a light at the top so you can see the thing in the rain or at night.
haha, I bet you would get some weird looks from people when you use it
I would put a little flag Vancouver Canucks flag on it and extend it up while I am beside people in traffic... should get some good reaction from Flames fans here