At first, I'd think: "Oh. She's obviously not from aroud here, then. She's actually kind of pretty, too. Good for her."
And then I'd just go my merry way, unless she's a classmate or co-worker-- you know, somebody I didn't just see on the street-- and attempt to assess her feelings towards yours truly over the course of two months. If she tests positive for possible romanticism, then I will file away a notation in the back of my head to maybe hit it off some time; and if she displays open attraction to me or no attraction at all, I shall behave accordingly.