A personal digital assistant is a friendly thing, and not much good for offensive action. The worst thing you can do with an iPaq is give someone a small bruise on the upper arm, or possibly squash their favourite stick insect. Or so I thought. But Matt Loney passed the following email on to me today from someone who we'll just call Doctor X: "I read your article about Intel's 3D graphics toolkit for its XScale processor. What interested me was the 3D demo on the HP iPaq handheld computer rendering on its screen, in real time, a fly-over of a detailed 3D landscape. Do you have any more information about that demonstration or a contact at Intel that I could call to get more information? I work at a US Navy R&D lab and we are in the midst of developing similar capabilities on an iPAQ. Thanks for your help XXX@XXX.navy.mil Well. While the US Navy has been known for its fascinating experiments involving running warships on Windows (subsequently towing them back to base while jolly Jack Tars signalled "Please Don't Hit Us" in semaphore from the darkened decks), the idea of modern warfare being conducted through Pocket PC 2002 brings a whole new meaning to friendly fire. User-friendly fire, perhaps. Our mystery caller doesn't tell us exactly what he's working on -- no doubt wisely -- but you can imagine that a troop of squaddies advancing through an urban environment would appreciate data from an unmanned spy plane loitering above the streets. If you can plan your next advance by virtually crawling through a 3D model of the city ahead captured moments beforehand, it saves on unpleasant surprises. Nobody likes surprises in that environment. But of course, the enemy will know what you're up to and will be trying to upload fake data to the flying eye above. What better way to get rid of those awkward visitors than to make them walk of their own volition into an ambush? And, of course, there's no reason why the modern battlefield should remain the last workplace on earth bereft of advertising -- we can look forward to banner ads for beer, guns and alternative employment, quite possibly chosen according to the intensity of the conflict in which the PDA-toting soldier finds themselves. Truly, a whole new world of warfare awaits.