Predictably, on the “taster” evening that follows, I am confronted with a  group of restless teenagers, ranging from the very serious, the out-rightly arty, to the "I don't -even- know- why- I -am -here- tonight, I -couldn't -decide -on- anything -else"- types. When I ask the question: "how many of you have brought a camera?" two hands go up among the assembled group of sixteen.  A challenging start. "Ok", I say, "who's got a smart phone or tablet with them? "- to which ten more hands go up. Time to think on my feet!