I've always been a big fan of VR/AR usecases. I made another post recently about zoloft and was amazed how placebo was often just as effective. I was a rare google glass defender. I know it's not quite what you were saying but it reminded me of this.

Google glass had the limitations that meant it couldn't stuff ads down your throat, while being useful for real hands free tasks. Navigation while walking around a city, hands free picture taking from your current perspective, basic web searches to get an answer in your eye while your hands are tied up. It was such a simple but useful device and that's why it had to be taken away.