They are known as wearable computers and are yet to hit the streets, but already they are creating controversy.
Google will soon give away and trial 8000 pieces of high-tech headwear known as Google Glass - a computer with a head-mounted display that can run apps, record high-definition video and is operated through voice commands - and plans a broader launch later this year.
Already, a range of Glass apps have been announced or demonstrated, including those for Facebook, Path, The New York Times, Gmail, JetBlue and Skitch.
Google said the technology could tell you the weather forecast, provide directions, send messages and translate.
Researchers at Duke University have developed an app called Insight that can identify people by ''visual fingerprints'' such as their clothes, body shape and motion patterns.
According to University of Wollongong associate professor Katina Michael, it will allow wearers to ''share visual surveillance in real-time with people in underground networks of all sorts - for the distribution of child pornography, for grooming, cyberstalking, voyeurism and even for corporate fraud''.
Its arrival has caught the attention of Australian Privacy Commissioner Timothy Pilgrim. He said he had requested a briefing from Google on how it would address privacy concerns.
''At this early stage the full implications of this technology, such as how people will use it, and for what purposes, are unclear,'' Pilgrim said.
The commissioner's spokeswoman said while Australia’s Privacy Act did not cover individuals, it was possible the technology could be used to breach state surveillance laws.
Some critics fear Glass will infringe cultural norms and protocols around when it is permissible to record images in both public and private.
For users, they may end up being overloaded with notifications and ads that, being right in front of their eyes, are difficult to ignore.
Several amusing parody videos showing supposed real-world uses of Glass have gone viral, such as getting drunk (and arrested) on St Patrick's day or a man on a first date who researches his companion and even watches sport while still sitting opposite her.
A campaign against the technology, dubbed Stop The Cyborgs, claims an uprising against the technology is essential to save privacy and even humanity.
Its backers have begun issuing Google Glass ''ban signs'' and encouraged people to install them in homes, offices, restaurants, bars and other public places.
Google Glass users have been dubbed ''Glassholes'' by sections of the blogosphere, but defenders say a few geeks walking around with camera-equipped glasses are the least of our privacy worries.
Professor Bruce Thomas, director of the wearable computer lab at the University of South Australia, said the criticism was overplayed.
He said people already had personal tracking and surveillance devices in their pockets.
''I do not hear people proposing banning phones with cameras,'' he said.
Australian futurist Ross Dawson said that people largely accepted widespread video surveillance, but ''the idea of individuals recording video wherever they go is more pointed and uncomfortable''.
He said the technology may be the final straw in the erosion of privacy that sparked a social uprising and new legislation, but it was more likely that people would become used to ''a world in which almost everything they do is visible''.
Australian inventor Mark Pesce said Glass raised questions such as whether it was safe to drive while wearing the device.
"There are also questions relating to whether it is a good idea to have a fixed-focus device pointed into one eye - it can cause continuing eyestrain," he said.
For Google, not even having to take your phone out of your pocket to interact with its services could allow it to show you more ads, more often.
Naturally, it would also hoover up even more data about wearers. Google co-founder Sergey Brin has said he wants to make Google "the third half of your brain".
Analysts ABI Research expect the wearable computer market will grow exponentially, predicting there will be 485 million shipments a year by 2018.
A Microsoft executive said recently he expected we would all be wearing 10 sensors on our bodies in 10 years from now.
Apple is rumoured to be developing an iWatch and devices including the Nike FuelBand and the Pebble smart watch are already on the market.
A spokesman for Google said the Glass product was in its ''very early days'' and that, as with mobile phones, it would take time for behaviours and social norms to develop.
Professor Thomas said: ''The big thing that Google's trying to do is: 'Let's actually make a product that people have been talking about for 15-20 years and just see where it goes'… That's the real interesting question.''
- Sydney Morning Herald