As a rule of thumb the first people who are going to use extensively the wearables are the people whose work is a matter of life and death.
It is very important in an army to have an edge other the enemy, that is what we have always seen in history, and moreover the army is known to spend vast amount of money in order to get this edge.
Some years ago the infantryman was ordered to carry different pieces of ordnance that came from different sources and were not part of a whole thing, and to try to do his best with theses ( looks like Frankenstein to me ). With theses new projects the infantryman is the centerpiece of a coherent, complementary weapons and equipment system.
In Australia there is a program called Land 125 Soldier Combat System ( formerly "Wundurra" ( the aboriginal word for Warrior ) ), there is some information on DTSO's website; and according to the ATSE this project should be on phase 2 on year 2000/2001.
According to DTSO the soldiers should have intra-section radios, night vision and sighting capability and head up display.
In France there is a project called FELIN ( Fantassin à Equipement et Liaison Integrées ( Foot soldier with integrated equipment and links ) )
in order to enhance the efficiency of the soldier a set of devices had been developed with very careful limitations : historically the foot soldier has been a beast of burden, thus the FELIN project wishes to limit its load at 25kg. The soldier has got a radio link, a computer and a camera on his weapon ( allowing him to open fire from cover ). The display is done with a monocular HMD.
The FIST ( Future Integrated Soldier Technology ) project: Early tests were conducted on Salisbury Plain to determine if the soldier could access information either 'Head Up' ( in a helmet display ), 'Head Down' ( on a wrist mounted display ), via a palmtop computer or if necessary a map
lessons learned ( in L'armement issue 67 September 1999 )
It is a system made of 5 subsystems cooperating together.
The location of each squad member will be available through the IHAS, as well as digitized maps and tactical information. Every soldier will have an integrated GPS as well as video recording capabilities. Of course the soldier will have night vision capability as well as deported sighting. Tests should take place during year 2000. More info on the Land Warrior program at
http://www.sbccom.army.mil/programs/lw/index.htm
( There is even a FAQ and pictures ). AFAIK this is going to be the biggest test for the wearable concept because the Army is planning to purchase 34000 units plus spares.
During the summer 1999 news poured that the US Navy tested the Virtual Retinal Display at Hawaii. The explanation is that there doesn't seem to be enough space in the fighting ships because of the numerous CRT, so it is conceivable for the crew to wear VRDs
Needless to say, that some very low profile and highly specialized units should have adopted the wearable concept but as far as we cannot have evidence we can only speculate on that.
The Microvison's VRD has been delivered to the Wallace Kettering Neuroscience Institute, Dayton Ohio, for neurosurgery applications. This is not a full featured wearable solution but it is a big step toward the adoption of wearables in health care activity. ( on the website you can view a simulated image ).
Firefighters are using thermal cameras in order to see through the smoke, in the next years theses devices should be miniaturized and with a wearable firefighters should have both hands free and will have real time access to data such as the map of the building and numerous helpful informations.
One can easily think that a wearable computer can be very helpfull for the disabled people, for example for blind people a wearable with a GPS receiver, some maps of the surroundings and even more, interacting with its surroundings by means of active beacons can be a very good substitute for a dog, the elements exists for a long time.
This should be easily done : the linux comunity has good text to speech applications, voice recognition is quite ready for this application , the IrDA or Modem radio drivers are OK, the same applies to the GPS programs, we have to develop an electronic blind walking stick in order to detect the obstacles at a much reater range and last, but not the least to convince the autorities.