The new Swiss Army knife contains 85 devices, weighs 2lb and costs nearly £500. But can you actually use it for anything? Andrew Martin puts the ultimate tool to the test

Swiss Army knives are obviously good things to own. They're standard equipment for Nasa's astronauts, and feature in the Museum of Modern Art in New York as an example of outstanding functional design. When Chris Bonnington headed a Himalayan expedition in 1970, he used every one of the blades in his Swiss Army knife except the fish scaler; as he apologetically pointed out to the manufacturers, there are no fish on the south face of Annapurna.

In 1989 Professor John Ross, a doctor in rural Uganda, wrote that he had used the saw blade attachment to perform six emergency amputations, his surgical saw having been stolen. I myself have brought many a seemingly desperate situation to a happy conclusion by the employment of the corkscrew on my own Swiss Army knife. The only downside to owning one is running into somebody whose model features more implements than your own.

If, for example, I owned the Swiss Army knife called a Scout, humbly equipped as it is with only a can-opener, a large blade, a nail file and nail cleaner, a cruciform Phillips screwdriver, a reamer, another screwdriver, a cap lifter, a wire bender, a toothpick, tweezers and a keyring loop, and I went on a camping holiday with a man who owned the Engineer, which incorporates everything in the Scout knife plus tag clamp, wire cutter and pliers ... If that happened, then I'd probably pretend that I didn't have a Swiss Army knife at all, rather than be revealed as someone who could bend wire all day long but not actually cut it, and who was completely unable to tag any clamps - or clamp any tags, as the case may be.

Just as you can't be too rich or too thin, I'd always thought, so you can't have too many tools on your Swiss Army knife - but that was before I took delivery of the new Giant Swiss Army knife. Grotesque, if superbly engineered, the Giant weighs nearly a kilogram and features 85 devices in all. Unload this mother into the plastic tray as you walk through security at Heathrow and just see what happens.

The Giant is supposed to feature every blade that has ever been incorporated into Swiss Army knives as made by Wenger, one of the two firms that make them . "We've sold 20 to retailers so far, and we can't get them in fast enough," says Garry Woodhouse of Whitby and Co, sole importer of Wenger knives into Britain. "They're assembled by hand in Switzerland, and I'm told that the man doing it is working his fingers to the bone."

This might explain why my version of the Giant seems to have its tools arranged in a different order from the listing on the Wenger website, so that I am in danger of mistaking the reamer for the golf-club face cleaner, or committing the faux pas of attempting to use the fish-hook disgorger to tighten my bicycle spokes. And I admit that I just can't find some of the devices that I know are definitely in there: the mysterious "special key", for example, or the elusive "12/20 gauge choke tube tool".

None the less, I have successfully employed the cigar cutter, the flashlight, the laser pointer with 300ft range, the mineral crystal magnifying glass (rather beautiful, the way such an apparently delicate instrument is honed at its end into yet another screwdriver), the tyre-tread gauge measurer and the corkscrew. It took a mere four minutes to remove the cork with the Giant, incidentally - a matter of holding the bottle between my feet, leaving both hands free to revolve the cumbrous contraption.

The Giant is a real product, available for the very real price of £495, but it is aimed at completists and collectors. One gadget website correspondent has balefully written, "I envision this monstrosity being presented as a rare 'salesman's sample' on 2310's version of The Antiques Roadshow." Wenger admit that its practicality is limited, and that its purpose is partly to promote the company .

Wenger was not the first company to make Swiss Army knives. That was Victorinox, founded by the Swiss cutler Karl Elsener, who was appalled to discover that the Swiss army was supplied with knives by Germany. He began making knives for his country's armed forces , and from 1893 faced competition from another Swiss firm - the one that later became Wenger. In 1908, the Swiss government brokered a deal whereby the army would take half its knives from Victorinox and half from Wenger. Victorinox would be allowed to claim that they made "the original Swiss Army Knife", while Wenger would be allowed to call theirs "the genuine Swiss Army Knife".

This gentlemanly disbursement of epithets will no doubt strike some as irritating: "Bloody Swiss. Always so bloody reasonable!" Such people will be further irritated to learn that when, in 2005, Wenger overextended itself with an ambitious product launch, Victorinox intervened in brotherly fashion, to acquire the company, preserve the brand and stop it falling into foreign hands.

But although Swiss rationality and neutrality are often mistaken for wimpishness, Swiss mercenaries were long considered the most reliably vicious in Europe. The infantrymen of the Swiss Confederation were particularly skilled in the use of very nasty-looking pointy things, including crossbow bolts and the 18ft pikes with which they fought off the Habsburgs at the Battle of Morgarten in 1315. (The pikes carried by the Papal Swiss Guard are an echo of this battle.)

Even George Bush might think twice about invading Switzerland, where every man is required to do regular stints of military service, and keeps his kit, including his gun and his knife, at home in between . The version of the knife that is actually issued to the Swiss army, by the way, does not feature a corkscrew. Versions with bottle openers, however, were particularly popular with American GIs, and today 50% of Swiss Army knives are sold to America. I'll bet that most Americans who own a gun also own a Swiss Army knife. It off ers the same fantasy - ever more attractive in our apocalyptic age - of self-reliance in extremis. The very chunkiness of the Giant knife points up the liberating portability and specifi city of most other versions, even the "white collar" knives such as the Ambassador, which features a toothpick (for the reflective aftermath of all those banquets) but not, of course, a can opener; or the Manager, which features an orange peeler for those craven lunches taken at the desk rather than down the pub with the workers.

The Giant does, by its grandiosity, court churlish responses. My 10-year-old son looked at it sceptically for a while, and said, "I'll bet it hasn't got a spirit level." But a more grievous omission on the face of it is the lack of any implement for taking the stones out of horse's hooves, which surely is the classic Swiss Army knife tool. Imagine paying out £495 for the giant knife, and to be sauntering down the road with it - or staggering under its weight - only to encounter a man with a horse with a stone in its hoof. "Sorry, mate, I can't help you," you'd have to say, "unless you think a golf divot repair tool might do the job." In fact, the stone-removing device is mythological, so the completist owner of the Giant need not be embarrassed . However, if you put to him - and of course it will be a him - the suggestion that his fingernails could do with trimming, he will probably change the subject pretty quickly. The Giant was conceived too late to feature the new Wenger fingernail-clipping tool, and a new extra-big Giant may eventually be produced that does include it. Meanwhile, all other presents for practically minded men are going to look pretty skimpy this Christmas.

· For stockists of the Wenger Giant knife, contact sales@whitbyandco.co.uk or call 01539 721032.