include marketing campaigns by companies such as SonyEricsson Finland and Nike Brazil. The corporations have printed the symbols on billboards, bottles, or even television ads and then asked customers to scan them to interact.

Application Considerations

When it comes to the new social use, there is a catch: People have to have a installed on their phones to be able to read the barcodes. ShotCode says its free app supports more than 360 different phone models -- including, of course, the iPhone -- but still, someone would have to take the initiative to install it for the thing to work. This requirement is no doubt the limiting factor of the technology. Until the idea gains widespread interest, you'll just look like a guy with a strange symbol on his shirt to the average observer.

There are also clear privacy concerns -- you might not want to walk around the city with your social network profile virtually stamped on your back for anyone to scan. Because of that, I suspect the social network shirts won't become an everyday, walking around the streets sort of commodity.

Still, the concept holds interesting implications for specific and limited scenarios. Imagine, for example, singles gatherings where everyone has a linked up shirt, or specific nightclubs that encourage the use of the technology on particular evenings. Even a private party where everyone invited gets a linked-up shirt could make for a unique sort of social experience.