Well, I've had a certain security guard call me 'sir' 4 times yesterday (so it's definitely not a slip of the tongue) even though I'm pretty sure I don't even look androgynous, let alone pass, at the moment. Once I even got a sir while the person behind me got a ma'am, so it doesn't seem like the guard was just calling everyone a sir. Pretty cool, but confusing.
Otherwise I'm pretty much a she to everyone..