The Android, Blackberry and iPhone have led the way in fulfilling a long-predicting prophecy: Bringing the Internet off the computer and out into the waking world.

The network service providers have adjusted to the change and the application stores are full of tools, or apps, aimed at helping us find the nearest restaurant, friend or point of interest (for example, the site www.mikarov.co.il, in Hebrew).

In the past year Twitter, too, issued a program interface enabling developers to produce location-based services for the site, but it is not the only one. Services like loopt.com and foursquare.com are attracting users to discover the world around them.

Many people are warning that the transition to having the Internet in every pocket will exact a price, though exactly what that will be remains a mystery.

The transition to 24-hour mobile Internet access is liable to entail the loss of much of our privacy. After all, the spread of GPS technology can allow others to pinpoint our exact location.

Nadav Aharony, a doctoral student and researcher at the Massachusetts Institute of Technology Media Lab, says the answer to the question "Where are you?" doesn't even scratch the tip of the iceberg with respect to the information a mobile phone reveals about its owner.

Yet, however great the risks may be - and he agrees they do exist - the potential inherent in the technology is equally great, both from research and standard of living points of view.

Aharony says studies on the topic fall into two categories - work with specialized tools, such as wearable sensors developed in the laboratory for various research purposes, and research aimed at discovering what existing handsets can produce in the consumer market.

This work is carried out in the Human Dynamics research group at MIT, headed by Prof. Alex Pentland, to which Aharony also belongs.

"All this work is a new kind of microscope - a means of making the social sciences more precise. People are a lot more programmed than you think," Aharony says, with more than a hint of sadness.

In studies using wearable sensors - kind of smart badges worn around the neck and equipped with various sorts of sensors - researchers have discovered that it is possible to predict a variety of behaviors with a high degree of accuracy.

"The idea is to discover the 'honest signals' - the signals beyond the contents of things," Aharony says, for example, "tone of voice, or if one of the sides is moving in a way that indicates impatience or boredom, or whether someone is unconsciously imitating his companion's manner of speech or behavior. We can predict with a high degree of accuracy, from the first minutes of a conversation between a salesperson and a customer, whether there will be a deal, or whether a group working on a group exercise can be expected to succeed at the task."

Aharony explains that "the data show in a quantitative way that if some particular person dominates a conversation, the entire group is less successful."

The sensors have proven themselves not only as a tool for gathering data, but also as a means of improving dynamics. One student found that if members of a group were shown real-time information on how much they talk, the dominant talkers would moderate themselves and allow for a more balanced discussion.

Aharony says that in the past, data was collected only from specialized sensors but "as time passed, we discovered that more and more of the sensors we developed are entering the mobile phone."

Thanks to the technologies that have been introduced to cell phones, such as Bluetooth, GPS, Wi-Fi and Accelometers, "the cellular handset is in effect becoming a complex sensor that can reveal things about you," Aharony says.

It is sometimes difficult not to recoil when Aharony relates how the researchers distributed sensors or mobile phones to scores of people and collected data on them in what he calls a living laboratory, and he indeed understands the feeling.

"Who is using this today?" he asks. "Advertising companies have thorough knowledge of persuasion technologies and use them to 'hack' into our desires, to persuade us to buy more and more. However, what if we use these same tools to cause people to stop smoking or to decide what we eat?"

For example, explains Aharony, "There is a correlation between measures of depression and social activity. Therefore, if mobile phones can detect changes in social behavior, it will be possible to identify depression, or even the development of Alzheimer's disease among elderly people, and to inform friends and family members. After a number of warning lights, it will be possible to recommend to the user that he seek help."

The disadvantages of location-based applications are also not yet completely known to the general public.

"When I go around with a mobile phone emitting the digital aura of all the identities and contexts I have, it's a physical anchor by means of which it is possible to keep me under surveillance and to harm me. The world of portable Internet is much more dangerous," says Aharony.

Superman and the risks of gaydar

Aharony describes a situation in which an American soldier equipped with a mobile phone that identifies both the location of his group of army buddies and anyone from the gay dating group to which he belongs. Today it is very easy to intercept wireless traffic and discover that a person is a member of both groups.

"Something is needed that will enable people to be like both Clark Kent and Superman," argues Aharony, "to be in the same room with two different people and to reveal different identities to each of them in a way that would make it impossible to know that they are one and the same and thereby keep them from using that information against them."

In the digital world today it is very difficult to separate a user's different identities. In the future there will be a solution to this, including technical aspects like various kinds of encoding as well as elements of standardized and enforceable legislation.

Users must also understand how to manage their privacy, and content providers must make this process opaque, so as not to spook them from using digital identities.

It is also possible that companies like Google, Facebook and others, which are built upon information about us, will want to relinquish part of the information and restore our anonymity to us. They may fear possible lawsuits or that encoding and privacy will come into play and users will choose to go to a company that stores information more soundly.