I think that would definitely be the "gold standard", but most of us have a fair idea what city the person normally lives in, which would narrow things down a lot. [EDIT: Just re-read the name of the thread though!]
It definitely has to be your own photo, it's too easy to find a photo reposted from online.
Here's one for you to try, it's not from today though unfortunately. Not sure if this is too hard or too easy, but see how you go: