Twitter 360 is one such from app developers Presselite. The idea is that it uses your phone’s camera view combined with your GPS position to show you where those people, which you follow, last follow tweeted from. The practical use in its current state is arguable but if, instead, their information overlayed onto the real scene were tags of locations where people had tweeted in the past, that could be more interesting. Rather than being about where your friends are now, it suddenly becomes more about the context of what people were looking at to inspire them to tweet in the first place - a bit like a series of very minor event blue plaques but possibly interesting nonetheless.

Of course, the major trouble with these apps, and those like them, are the way they work at present. The app finds your position through are frustratingly inaccurate GPS system, consults the Internet and then tells you what they think is supposed to be nearby. In terms of functionality, they’re arguably no better than getting the same information on a top down map, but what if we could get beyond that for a minute? What if your camera knew what it was looking at? We wouldn’t necessarily have to take it as far as the AR eureka moment of true computer vision, as we talked about in our interview with tracking expert Georg Klein. How about something which our phones can already do? Something as simple as face recognition. How about an application that, when you hold your phone up to a person, it knows who they are and then displays information on your screen all about them? This, in fact, is precisely what TAT (The Astonishing Tribe) demoed as a concept Android app at Mobile World Congress 2010 and what the Swedish design collective called “Recognizr”. It works by tying into your social networks so that, when someone hovers their phone over you, the app pulls down and displays whatever you’ve just posted on them.

Taken this far, suddenly our virtual and real life personae start to merge. Facebook began this migration from a hidden identity behind a keyboard and made up user name towards a more public online existence, one to which our colleagues and families became connected. Once strangers can get access to those privileges too, then the distinction between our two lives will have disappeared altogether, and there’s a number of ways it can go from there - some good and some bad.