The advertising industry is getting pretty desperate to keep our attention; there’s a lot of evidence that we’re becoming increasingly resistant to ads (after all, when did you last click on an Adsense square?), and more cities may follow the lead of Sao Paulo and ban billboards entirely. Until then, it’s the same old frantic war for your eyeball attention, and the lastest weapon is the Eyebox2 – a device that can track the attention of a number of people from up to ten meters away, hence providing feedback on the effectiveness of individual ads, or perhaps changing their content when attention starts to wane. There’s never been a better time to start up a street stall selling cheap sunglasses. [SmartMobs]