I'm not that interested in having a camera on my bike for recording rides but something I might find useful is a rear facing camera that had a display mounted to my handlebars. In other words an electronic rear view mirror since I've never found actual rear view mirrors to work all that well for me.

It is perhaps one application I could see for something like a google glass like device that doubled as sun glasses/winter goggles, - or maybe they could be called winter googles.

Yes, I know you can mount rear view mirrors to your helmet but i never seemed to be able to get one adjusted so I could easily take in what I wanted to see behind me. I found myself just looking back.