Popular Mechanics has a cool article in their January 2009 issue about a new binocular technology for the U.S. military. Called LightSpeed, these binoculars have high-power infrared LEDs that allow them to transfer data and voice at up to 1 megabit per second and 32 kilobits per second respectively. There is a receiver in the left eyepiece and a transmitter in the right, which can emit an undetectable beam up to 1.8 miles. So to transmit information to another person, you just have to look at them. Unlike similar systems that use lasers that can be harmful, this system is eye-friendly.