Those Google glasses that serve as a wearable computer are scheduled to go on sale later this year. I’m really curious to see how well the head-motion interface will work for someone like me. I’m guessing it won’t be as sensitive as the headset I use to operate my PC, but perhaps I’m wrong. Perhaps Google still needs beta testers to use these glasses on a daily basis. I’m willing to sign even the most onerous non-disclosure agreement.