A new line in clothing for Madge - but are celeb labels a good thing?

The time is 9am, on a cold, wet Thursday morning and I am standing, shivering, outside the Oxford Circus branch of H&M in central London. With me in a good-natured scrum are 30 or so women, most of whom are in their early 20s. But, for once, I don't feel too old to be here.