What do Hogwarts and Tottenham Court Road tube station have in common? Moving pictures, that's what.
On a recent trip to London I found that all of the advertising posters on the Northern Line escalator at Tottenham Court Road tube had been replaced by LCD displays. We've become accustomed to seeing these as one-off advertising displays in post offices and shops. However to be suddenly confronted by 40 or 50 of them doing no more than cycling through adverts for West End Shows, recruitment companies and sunglasses made me realise just how ubiquitous this new media is about to become.