There's no doubt that going out for afternoon tea is a special treat: the cakes; the scones; the little sandwiches. But tea-drinking is not just about leisurely afternoons spent overdosing on sugar: sometimes you just fancy a good cuppa. At home this is no problem - I need only open my overflowing tea cupboard and take my pick from the forty or so teas (!) therein. But what to do when I'm out and about?