A wearable computer should be always usable, always on, always ready to take and process commands. It is not acceptable for display to block your vision like it would do when there are two displays. If I'd sell these things, I'd like my customers to stay alive and not get hit by a car they didn't see. Really, a wearable computer is something you can use while moving around and performing activities. It's designed to free you from the desk. It's a lot more mobile than a laptop, and more usable than a smartphone, for so many reasons. Or at least it's supposed to be.
The Myvu Crystal is a nice item if you are going to watch movies on a plane. It's too bulky, heavy and looks too weird to be usable in public. If you have ever tested one, you know what I'm talking about. It's definitely not something you want to, or could use when running or working. You have to take the display off when working, and that makes the wearable unusable then doesn't it? A wearable is able to augment your mind, for example by showing you the cake recipe while baking, or a 3D model of a house while you are building it.
Also, wearables will not be a mainstream stuff for a while. Probably not for 10 years at least. They'll first be used by professionals of different fields. First geeks, then maybe doctors, policemen, firefighters... When you do stuff as a profession, the coolness factor gets less important. If a doctor can see the x-ray pics and all patient info like blood pressure and pulse and whatever always, that might be of some help. We have lots of information and wearable computer could allow us to use it much better. And hey, bluetooth earpieces and such have been accepted, why not a nice small display?
How do I think a wearable should be made?
I do not think there is one true way to do it. There are usable versions where display is not used at all and it's replaced by sound. There are other usable wearable computers too. However I do think there is certain things that would help it getting more "mainstream".
- The rig should be small and comfortable to wear daily.
Small because it can be hidden. You should not look like a borg. Totally hiding it doesn't matter much while working though.
- Keyboard should be handheld, preferably a chording keyboard like a Spiffchorder.
Geeks will take wearable with chorders easily. It should not be harder than to learn typing on keyboard, and you can type everywhere. Some wearable users are known to record their conversations by typing.
- There should be optional keyboards.
After early adopters have adopted wearables, is the time for general public. They will whine about chorders, and might not even want to type while moving. There needs to be easy way to type, even if it's not as comfortable and fast as chording.
- Display needs to be only on one eye.
This is pretty obvious if you think about it. Blocking your vision is bad. Only way to go with two displays might be see-through displays done either by Eyetaps* or half-silvered mirrors. Two displays are weirdly used by the argument by those who say one display rig like on that article is too borg-looking.
- It needs to be available.
It has to be easy to make, and pretty open for geeks to adopt it. It also has to be cheap enough. Currently the way to go seems to be Beagleboard + hacked Myvu Crystal + any portable keyboard + AA sized batteries. I did it that way, This Martin Magnusson did it that way, Gregor Richards did it that way... It's available and cheap and easy to make, there is certainly a pattern.
(* Eyetap was invented by Steve Mann. You look at display, and there's a camera recording what you would see without the display blocking your eye. Then computer can add stuff to your vision. That's how augmented reality vision will be done with wearables.)