Just about anything seems possible in the world of robotics, to judge by the surreal scenes last weekend at RoboNexus, the world's first consumer robot exposition, in the heart of Silicon Valley.

A weightlifter wearing an "exoskeleton" machine suit lifted more than 1,000 lbs. Two sumo robots, following rules resembling Japanese wrestling, tried to force each other out of a circular arena. Humanoid robots danced and cartwheeled for appreciative audiences.

Thronged by more than 10,000 visitors of all ages, the trade show buzzed with a sense that robots are about to cross a new commercial threshold - but no-one could say exactly how. Few exhibitors had a clear idea of which technology, product or business model would catch the imagination of the consumer market.

RoboNexus was, in effect, a coming-out party for an industry whose sales are expected to double from 2002 to 2005, reaching more than $5 billion (€3.94 billion) in 2005 and as much as $17 billion by 2010.

Silicon Valley veterans said the atmosphere recalled the early days of Comdex, the Las Vegas computer show that became the technology industry's main annual event before the downturn.

White Box Robotics is a small start-up that exemplifies an industry in search of itself. For about $1,000, White Box Robotics will sell a stripped-down personal computer built on top of a robotic drive train. Consumers must install a hard drive and operating software, as well as modify the unit to suit specific needs.

For example, the owner could add a camera and speakers, and speech and voice recognition software, enabling the unit to serve as a security robot or to monitor elderly patients by remote.

Tim Novak, White Box Robotics spokesman, said the robots could do more if customers put in an MP3 music player, a wireless keyboard and monitor, or even a tread-based drive train.

But ask him what these units will do for consumers - what "killer app" (application) will make these robots indispensable - and he shrugs, adding that the company hopes customers will lead the way. "We want to know what people are doing. We're going directly to the market to act as our research and development arm."

Dean Kamen, inventor of the Segway scooter, said the pioneer mentality was all too evident at RoboNexus. "That's what's exciting about all new industries. You almost always get it wrong at first," he said.

iRobot, maker of the Roomba' robotic vacuum cleaner, did not get it wrong. The company scored an early hit - more than one million Roombas sold - by building a reasonably priced robot that performs a household chore most people hate. The company has been coy about future products.

Many at the show suggested iRobot would soon market a robot lawn mower, while others wistfully mused about robot bathroom cleaners and window washers.

Dan Kara, founder of Robotics Trends, the market research firm behind RoboNexus, said a new generation of service and consumer robotics companies was trying to emulate early industrial robot makers.

Several healthcare robots are already carrying equipment and shuffling medicines in hospitals countrywide, but Mr Kara said the market has the potential for much greater rewards.

Mr Kara came to Silicon Valley because it is home to many of the best researchers, as well as a number of venture capital firms and trend-setting enthusiasts.

Representatives from some of Silicon Valley's corporate giants took advantage of the opportunity to promote their views. Mr Wright, the Sun engineer, says his company hopes its Java programming language will be used to programme robots and connect them to the internet.

While many industry insiders agree that Linux, the free open-source operating system, is emerging as the de facto standard, a Microsoft representative was on hand to talk of his company's support for PC-based university robotics research.

Organisers said almost 300 venture capitalists, investment bankers and financial planners were milling about.

"This is like Comdex in 1980," said Donald Morgan, a Smith Barney financial planner. "Who wouldn't want to have invested in microprocessors back then?"