Katie Holmes, Olivia Wilde And Gerard Butler are among the big names who will host New York's free Global Citizen Festival on 28 September (13). They will be joined by will.i.am, Erin Heatherton, Deborra­-Lee Furness, Karolina Kurkova and Freida Pinto. Alicia Keys and John Mayer will headline the event, which aims to help tackle poverty worldwide.