There was a face in my picture i'm not sure what it is someone

I was taking a picture off myself for my twitter page and when i looked at the picture i seen myself and like a face with like a haze around it to the side off me and i took it with my new iphone 4 so its not the camera, so does anyone have any ideas what it could be? I'm creeped out

Probably a double exposure. Don't send your picture to ANYONE, it could be missused.