Face it - the average robot you see on the news these days makes the Iron Man in The Wizard of Oz look incredibly sophisticated. Today's robots can only wander about, apparently afflicted by rickets, wave woodenly and make stupid statements in a thin, metallic voice. Imagine being stuck in a lift with one. Most robots, however hi-tech, belong on the scrap heap with the manual typewriter and the Segway. But one breed of robot scuttling about at the fringes of science has been causing a persistent buzz lately - the millibot. The word means a miniature robot resulting from the giant strides made in the rapidly developing field of nanotechnology - the science of building almost unfathomably small things. Yet, despite their lack of stature, millibots have already been portrayed as monsters. Having swapped dino for nano in his latest thriller, Prey, Jurassic Park author Michael Crichton portrays millibots as avenging furies. The story: a cloud of millibots, dubbed 'microrobots' in the movie, has escaped from a laboratory. This cloud is self-sustaining, self-reproducing and clever enough to learn from experience. Effectively, it is sentient. Better yet, it has been programmed to be a predator and is evolving swiftly, becoming more deadly with each passing hour. Every attempt to destroy it has failed and guess which creature the millibots prey on. So far, however, the only actual millibots to have gained any publicity - the 5cm critters under development at Carnegie Mellon University's Robotics Institute - have yet to record their first kill. Moreover, they could prove more of a blessing than a bane. En masse, they are just as capable as bulky robots, according to Pradeep Khosla, department head of electrical and computer engineering at Carnegie Mellon. Tiny robots working in harmony would supposedly be as effective as a single big, better-equipped robot if they could negotiate physical obstacles. To that end, Carnegie is investigating the possibility of mobility platforms that will enable a group of robots to help each other like a train in which all robots conspire to shove the lead robot over an obstacle. But the main advantage of millibots is that they can access spaces impenetrable to their larger counterparts. Small robots can crawl through pipes, inspect collapsed buildings or hide in small, inconspicuous spaces. For surveillance and exploration tasks, this ability to nose around could make millibots formidable sources of intelligence just like the mechanical spiders in the Tom Cruise film Minority Report. Tininess has plenty of technical drawbacks, such as limited mobility range. Worse, millibots raise some concerns beyond the realm of the humans-for-breakfast sci-fi scenario. For one thing, microscopic millibots could potentially crawl into human orifices and embed themselves there. Ouch! For another, there is the menace of sinister new weapons called 'molecular disassemblers' that could raze buildings, and nanobots programmed to destroy an enemy cell by cell. Given the billions in investment that nanotech attracts, these scenarios are bound to make public relations people shake their heads and smile condescendingly. Even if they are hysteria-based, the debate they engender could prove damaging. Remember the biotech food battles of the 1990s, when Green groups mobilised, damning one line of genetically modified seed research by Monsanto and the United States Department of Agriculture as 'Terminator technology'? As a result, the research was killed off. If Prey becomes a box office smash on a par with Jurassic Park, which looks likely given that Crichton has sold the movie rights to Fox for US$5 million, the march of the millibots may be halted. Confused by computer jargon? E-mail firstname.lastname@example.org with your questions.