It is customary to view robots purely as mechanical devices, but as the cost of processing power and related technologies continues to fall they are turning into internet-enabled computers with attitude - on wheels, or even on legs.

Two separate, and contrasting, announcements last month underlined this trend. UK-based RoboScience launched the labrador-sized RS-01 RoboDog - the world's strongest and largest commercial legged robot.

And Japan's NEC unveiled PaPeRo (for Partner-type Personal Robot), whose natural expressions and ability to remember its owners' interests and preferences are designed to offer a friendlier interface between humans and machines.

RoboDog's tricks, such as carrying a child, performing a handstand or reading out e-mails, guaranteed it coverage in media ranging from the broadsheet Financial Times to Rupert Murdoch's tabloid The Sun. True to form, the latter had the dog posing with a scantily clad model in a chilly London park. The dog looked happier.

But the behind-the-scenes story of the development of RoboDog and its onboard technology received much less attention.

It is claimed to be the first commercial robot running Microsoft's Windows operating system. RoboDog can communicates wirelessly with its owner's PC using standard internet protocols, allowing it to be permanently online.

With 64MB of Ram (Random access memory) the RoboDog is intelligent enough to understand and act on 60 verbal instructions. Alternatively, an onboard camera allows the owner to log onto the robot via the net and drive it around its environment, seeing and hearing through it 'eyes' and 'ears'.

Nick Wirth, the former Formula One designer and co-founder of RoboScience, sees RoboDog as a "technology demonstrator" that gives a strong indication of how robots may develop in future. A current PC, he says, has the computational performance of a simple reptile, such as a lizard. However, over the next decade PCs are likely to grow in speed to equal the brain of a mid-order rodent, such as an otter.

RoboDog's development is also a noteworthy example of collaborative commerce. This fast-emerging trend in product development involves teams of designers and engineers from different companies, working in various locations, using the internet to collaborate.

As aresult, it took Mr Wirth and a team of seven specialists only seven months to turn RoboDog from an idea into a working prototype.

This required the use of advanced software - from US-based UGS Solutions - that would allow complex design information to be shared over the internet. The Unigraphics software suite was critical not only for enabling design and technology breakthroughs in RoboDog's joints and body, but also for integrating styling, engineering and manufacture.

As is becoming increasingly common in modern manufacturing, the development team decided to save costs and time by dispensing with elaborate physical mock-ups, doing all the styling and engineering work on screen before building a fully working production prototype.

All 3,000 components for RoboDog fitted together first time, without any rejection or reworking -a "unique achievement in complex design and manufacturing projects," according to Mr Wirth. Collaborating over the internet was "a very interesting model for a 21st-century company," he says.

NEC, meanwhile, claimed its PaPeRo personal robot was unlike anything so far seen in robot development. Designed to partner people in their homes, it illustrates developments in both voice and image recognition technologies, and in speech synthesis.

PaPeRo, says NEC, can recognise 650 phrases and speak more than 3,000. Like RoboDog it can notify its owner of incoming e-mails and offers easy access to the internet without use of a keyboard. A stream of visual data from its two cameras can be analysed in real time, enabling it to recognise people and avoid bumping into objects such as furniture.

While it exploits advances in IT, PaPeRo is also designed to help users cope with the increasing complexity created by the pace of such technology developments in computers and communications, which many people find overwhelming.

From children to the elderly, there is a growing voice for technology that is simpler to use, says NEC. Robots that live with, and have the ability to interact with, humans in many different ways will open up many possibilities, it says.

"The aim of our research at NEC is not just to further robot technology, but to examine and develop better human-machine interface through the concept of 'living with robots'," says Yoshihiro Fujita, project manager at the NEC Incubation Centre near Tokyo.