On the BBC website

'The BBC's Kevin Connolly, in Chicago: The crowd that has been gathering all day around Grant Park was finally allowed in around an hour ago. They arrived cheering and screaming and racing across the fenced off area of grass in front of the open air stage in a good natured competition to get the best places. As they did so they offered a clue as to Obama's methods - he brought politics to the rock festival generation, and they rewarded him by bringing rock festival style energy to his campaign.'