[TeMPOraL]

You never know when the smartphone camera is recording either.

[k__]

Wearing a Google Glass is like someone pointing a smartphone cam in your face all the time.

Yes, you get all the fancy AR stuff with camera, but I think you could still build a nice HUD without the cam.

[kbart]

True, but Google Glass is more like camera pointed directly at you. If somebody kept pointing smartphone camera at me constantly, I'd sure get annoyed.