Common wisdom is that you want your camera to be just above eye level slightly looking down on you. The camera pointed up at your face is "unflattering."
I am 6'4" tall and so everyone is extremely used to looking up at me and it even can feel very strange seeing a camera looking down at me ;P. But I am more asking about stuff like "there is research which shows that if you are looking down you look like you are hiding something but if you look up it looks like you are arrogant or distracted or [fill in the blank]", not "is this a flattering camera angle" ;P.
