British troops in Afghanistan are flying a drone that's shrunk down to its essentials: a micro-machine that spies, built for a solitary user.

This is the Black Hornet. Its Norwegian manufacturer, Prox Dynamics, bills it as the world's smallest military-grade spy drone, with a weight of 16 grams and a length of 4 inches. Propelled by two helicopter blades, the Black Hornet carries little more than a steerable camera that records still and video imagery. (That is: It's unarmed.) Now British soldiers have brought it to Afghanistan, as it fits in the palms of their hands. It's supposed to be a drone for an Army of One.

"We use it to look for insurgent firing points and check out exposed areas of the ground before crossing, which is a real asset," Sgt. Christopher Petherbridge of the Brigade Reconnaissance Force told the British Ministry of Defence for a Monday announcement.

The fruit of a contract initially worth $4 million that the Ministry of Defence inked in 2011, the Black Hornet is a major step in the recent trend of miniaturizing drones. The U.S. has its own shrunken spy drones: The Raven can be launched by hand; the collapsible Switchblade fits in a rucksack; and on deck is the insect-inspired miniatures at the Air Force's "Micro-Aviary." But it's currently got nothing as petite as the Black Hornet – although the Ministry of Defence is confident the nano-copter is rugged enough to withstand Afghanistan's harsh conditions.

What's perhaps more significant than the Black Hornet's size is its personalized application. Prox designed it to be a one-man intelligence, surveillance and reconnaissance package. The video imagery captured by a Predator, by contrast, has to supply a lot of people (even if only a handful of airmen operate its ground control station). There aren't that many Predators, and getting clearance to fly each one requires going up the chain of command. The smaller Raven pushed that spy capability down to company level.

But the Black Hornet is designed to be the robotic, remote-controlled eyes of a single soldier. Its imagery is transmitted down to a personal device that looks kind of like a Game Boy. A handheld mouse-like device steers it. While it's way too early to say how much value it actually adds in wartime, the Black Hornet hints at a future where recon soldiers and marines get kitted with their own cheap spy drones, the surveillance equivalent of the smartphone.

The U.S. military is far away from that future, especially as budget cuts set in and the ground wars wrap up. But the Army, at least, has been all about pushing data down to an individual soldier on patrol through her own handheld smart device. It might be interested in playing with its British counterpart's latest tiny drone.