Let's face it: without stormtroopers, Star Wars would be a lot less cool. The Rebels are stuck with orange jumpsuits, dodgy tunics (stand up, Admiral Ackbar) and over-sized helmets, while their Imperial counterparts strut around in the pimpest-looking outfits in the history of sci-fi. The stormtrooper aesthetic is the perfect fusion of style and menace: crisp and gleaming white (yes, white! The bad guys wear white!). The helmet is insectoid, detached, inhuman. The equipment is state-of-the-art, from blaster rifle to belt-held thermal detonator. Significantly, it's the only costume from the original trilogy that still looks futuristic 30 years on.

Their enduring popularity is evident, from dedicated websites to the reconstructed costumes flaunted at geeky conferences. There are a variety of flavours to pledge allegiance to: as well as the plain old ;vanilla' troopers, a long list of speciality divisions including snowtroopers (ice-boots, burka), scout troopers (funky visor, speeder bike) and sand troopers. Non-canon fan fiction has created even more, from magma troopers to shadowtroopers - which are, says Wookieepedia, "stormtrooper-Dark Jedi soldier hybrids".

Whatever their training, stormtroopers share an absolute allegiance to the Empire. What they also share is an inability to fight effectively, something which has turned these faceless soldier-drones into hapless comedy icons. A New Hope attempts to instil them with some genuine menace, as Ben Kenobi, holed up in the Tatooine badlands, whispers of their deadliness: "These blast points; only Imperial stormtroopers are this precise."

If so they proved, the Rebellion would certainly have failed. Instead, they run around the Death Star like space-age Keystone Kops, continually failing to hit their targets and, in the case of two particularly useless troopers, getting bopped over the head by our heroes.

Somehow, their ineptitude has made them all the more beloved. There's particular affection for the one poor grunt who bumps his head on a door in A New Hope. The clip has been visited more than 850,000 times on YouTube, and George Lucas, aware that he'd never manage to erase this blooper from the minds of fans, went the other way and added a comedy "boink!" sound effect on the remastered DVD.

Outside of the films, the cult lives on. There's the Cops-spoofing fan short, entitled Troops, that depicts them as beleaguered law-enforcers on Tatooine; a camp, all-singing, all-dancing appearance on the Donnie And Marie Show Star Wars Special; a guest appearance at a Microsoft rally in 2005; and most recently, a spectacular formation of 200 infantrymen at this year's Rose Bowl Parade - according to one breathless commentator, "the largest gathering of stormtroopers ever assembled".

They might not be able to shoot for shit, but they sure can march.