4.00pm: It all ends. Finally. After what feels like just 500 short years, the Harry Potter film franchise tonight comes to a finish. Or at least starts the beginning of that finish - the world premiere in London being only the first of many before the actual opening date (next week). And then there's the DVD and Blu-ray etc, so actually it'll be 2013-ish before we can stop hearing about the boy wizard.
But anyway, for the next three hours join us as we watch a live video stream of the festivities in Trafalgar Square, where the cast and crew will