From a photographer’s perspective, Instagram offers a way to share pictures from your cellphone with friends, but there's a whole other side to the service. The huge number of photos that users upload every day — more than 5 million as of April — means there’s a treasure trove of public data for the enterprising developer to play with. This is Now uses the Instagram API to display real-time (or close enough) streams of public images taken in five cities around the world, ranging from London, England to Sao Paulo, Brazil. Watching the procession of carefully composed and filtered photos of New York and Tokyo stream across our monitors, we wonder if this isn’t the perfect encapsulation of the mobile web.