I really wish Glass-style HMDs had taken off... I've built my own, but it's useless if the sun is out at all. I just want something unobtrusive and inexpensive that I can drive with a real computer.
Vuzix Blade would be fine too, just something that has a display you can look at when you want to and ignore when you don't. The Blade is way too damn expensive, though.
The device is completely abandoned by google by the way, but at least it can run normal Android apps so it can still be useful.