The fad may seem bizarre, but not, at first sight, such a huge innovation. Looking after a virtual pet, after all, is not so different from taking teddie bears on a picnic, endlessly combing a barbie doll's hair, or even, for that matter, looking after a real pet.

And even the most technologically challenged can see that the programming and engineering needed to produce the device are probably a doddle.

But the cute little egg does have one revolutionary aspect: unlike almost any other invention you can think, it aims to create, rather than eliminate, work.