Wired on Friday: These days, more and more, robots are in the air - sometimes literally. In Silicon Valley homes, robotic vacuum cleaners are a standard feature.

By many definitions, a thermostat, a bread machine and a dishwasher are all robots invading our lives - reacting to their environments, doing the work that previously would require a person's attention.

But, let's face it, that's not what we had in mind when we imagined the 21st century peppered with robot helpers.

Still, roboticists like David Calkins, president of the Robotics Society of America, talk about a revolution in the works that may take us closer to our imaginary robots than most commentators would dare predict.

Like most revolutions, it's been a long time coming. The big hold-ups, says Calkins, were efficient, lightweight batteries and visual processing. As those two features inch closer to reality, so has a community grown up that aims to bring real bi-pedal, humanoid helpmate robots to fruition.

If Calkins thinks he has seen this future, it's because he's been to Japan, where robots are more eagerly awaited even than the West.

That's led to "Robo Ones", miniature anthropomorphic robots that can walk, dance and even tumble. They wrestle and play, and generally show off a flexibility that hasn't been matched in amateur robotics before.

The importance of the amateur market of Robo Ones is simple; cost. You can build a Robo One from a kit for a little over $1,000 (€780). Compare that to anthropomorphic robotics projects at universities and corporations: you don't get much change from under a million.

Audiences at the recent Robogames in the US, one of the only places outside of Asia where you can see these machines, connected with the miniature humanoids in a way that went beyond watching appliances. People held their breath when one of the thinnest Robo Ones stepped out of the pages from a magazine and danced around the stage.

When a humanoid robot walked forward and bowed, the emotional impact was palpable. Robo Ones may be the first generally likable robot for humans.

Roboticists began putting the pieces together for a "generalised" robot years ago. A specialised robot can only do one thing - like fit together a car or get dog hair out of a carpet. It may be better at that one thing than anything else on the planet, but it can never do anything else. That specialised function dictates its form: manufacturing robots will always look a bit like giant arms; Roombas hoovers will always skulk across your carpet.

A generalised robot, the holy grail that exists after the robotics revolution, is a robot that can do what you tell it to.

No one knows exactly what that robot looks like. Calkins, who imports the Robo Ones into the US, is putting his money on the anthropomorphic Robo Ones.

Japanese robot geeks watched Honda's humanoid demo bot Asimo and Sony's "dream robot" Qrio redefine what conventional wisdom thought bi-pedal robotics could do. Before those two robots, designed as expensive corporate marketing exercises as much as research and development projects, the physics of a simple task like walking or climbing stairs was thought just too hard for any amateur.

But, after watching the success of the big-name bi-pedal robots, scores of Japanese engineers and enthusiasts convened to their garages and started building Asimo's and Qrio's tiny cousins. Now they compete in martial arts matches and dance tournaments in Japan.

What is most likely to spur the adoption of robotics in the business world?

Calkins thinks it's the same thing that the ancients dreamt of - cheap, effectively slave labour without enslavement.

Japan has the most whizz-bang robotics industry and the business sector is no exception. No less than two receptionist bots have been recently rolled out, to rave reviews.

Rather more pragmatic, backstage robots are creeping into the US. High labour costs mean that a few low-level jobs are already slipping into humanoid automation. Simple line-following mail-sorters are trundling along the corridors of the US post office, large corporations and hospitals.

But are these the generalised robots? Sadly, no. They, and the Robo Ones, are still waiting for one last technology: visual recognition.

Visual recognition is the piece that would allow something like the Robo Ones to navigate your house and perform simple tasks - until a robot can tell a doorknob from a cat, it's not something you'll want roaming free in the average home.

Visual recognition isn't here yet. In the 1960s, it was assumed to be just around the corner. By the 1980s, artificial intelligence experts despaired that it would ever be possible. Now, we are more pragmatic. It may not ever be perfect, but it is perfectable. And, like voice recognition, it grows more tolerable with each year.

It's funny to see how much our dreams have been influenced by how close the future seemed to be. In the retro future of the 1950s, we of the 21st century drive around in jet cars, eat pills for full meals and have a Rosie the robot to do our house cleaning.

We've come some of that way, with our washing machines and dishwashers, but we still lack metal, or even plastic, manservants. We may not have to wait much longer; and we may be as pleased to see them as they will be to see us.