“But Eagle has the idea that we can put this data to use for ourselves. He wants to go into the friendship business. Imagine, he says, that we can switch on our telephones to a “promiscuous” setting. This means we’re open to chance encounters. Our phone works as a beacon, sending out our profile in radio waves to those around us. In the early days, this profile will be like the early days of computer dating. It will include a list of our interests. Swedish movies, say, or bicycle touring, French food. And if those whose paths we cross share these interests, our profile will pop up on their phones, and we presumably won’t mind at all when one of them touches our elbow and says, “I had a coq au vin to die for at this little bistro….” The Numerati by Stephen Baker

This passage struck me as both futurist and commonplace. As soon as I read it, I immediately thought of Loopt, which uses the GPS in phones to locate you and people around you with similar interests. Aside from one of my brothers, I don’t know anyone who is using Loopt for this feature. It’s so easy to forget how long and difficult it is to build up a critical mass for services that depend on a network effect. Would you have bought a phone if your phone book was only 3 pages long?

Baker discusses in the same chapter how a more advanced system would map our movements, our social networks, and our behavior. He proposes that such a system would make smart recommendations on friends and lovers. I remain skeptical.