The US Army is presently testing a belt that can act as a navigation device which will allow soldiers to navigate towards their objectives handsfree. According to the New Scientist, it is called a "Haptic Belt" which is a belt that provides feedback to the soldier via vibration, with haptic actuators installed in the belt, and can receive GPS coordinates  from a GPS device and orders from a glove that can trasmit hand signals to it.

Haptic technology is widely available, especially in many Android smartphones, typing in a message would give you tactile feedback, a gentle vibration which confirms that you have pressed a key. In the Haptic Belts, the feedback generated by the haptic actuators would "nudge" the solders into the proper direction, and also give recognisable feedback when a hand signal is issued by a squad leader which is immediately transmitted to the haptic belts. In total darkness, a hand signal is totally useless, and illuminated GPS displays would give their positions away.

Navigating this way would help soldiers keep their hands on their weapons and their eyes on their surroundings rather than looking into GPS displays. Commanders can issue GPS coordinates from the base, which would rather mean that soldiers can be remotely controlled in their directions.

To give you more an idea, here is a DIY compass belt which the owner calls the Clown Belt. It uses pager motors (these are devices which receive messages when cellphones were not yet around and still in use in hospitals) and uses a digital compass that knows which way is north and the it will activate the right motor. It is connected to an iPhone which can give bearing to determined destination.

Haptic systems, like this haptic compass belt, are also being developed to aid the blind. The Army Research Office are also working with AnthroTronix for a glove that can relay hand signals to the belt. This will allow a squad or platoon leader to deliver commands to soldiers, especially at night, using hand signals which are then transmitted to the belt to activate the actuators for the appropriate vibration for the soldiers to either halt, move forward, and so forth...

AnthroTronix is the developer of the AcceleGlove which was developed under grant by the US Army and Department of Education. The glove recognises static and dynamic hand and finger movements which transmits the data to a computer, in this case to the processors in the haptic belts, and is cost effective. You can developed your own applications as there is an SDK for you to work on and see what you can do with the Acceleglove.

I don't have a very good idea on how the Haptic Belt being developed for the US Army works, but to give you an idea, on how navigation orders are relayed by the belt, I have found a presentation in Finland by Lauri Immonent called "Haptics in Military Applications". The illustrations and photos below show possible configurations, setup, and feedback relay of the haptic belt.

The belt is connected to a GPS device which has an accelerometer and compass for the belt to know the proper heading. So far in testing, the soldiers are ok with the buzz that the belts generate, as these are gentle enough not to cause any discomfort to the wearer. What the soldiers appreciate about the haptic belts is that it allows them navigate along waypoints en route to objectives without the need for them to glance at a GPS device that will make them release their hands from their weapons.

Rather than holding a map, compass, and a GPS device which will also slow down a platoon or squad on their way to an objective, the haptic belts may help accelerate movement when time is of the essence. In the tests, the belts performed well, but there's no saying yet of when they can be given the go signal to be issued to soldiers in the field. There will be issues such as detection of signals in various situations such as laying prone, going through obstacles or being inside infrastructure. Signals may be blocked and users may still need to resort to the old school way of navigation.