Great idea! However, AirBnB should not only post the photo, but also be in charge of verifying over Skype that it matches the person posting it. If it'd be too expensive to verify every single new user, they could just verify them once they make their first booking.

AirBnB should be the one matching photos to real, living individuals since not everyone renting out their home is likely to be as through as a company with a well-established procedure.