Dermot O'Leary presents the first of this weekend's live finals as this series of the gold standard of popular singing contests draws to a close. The remaining contestants sing their hearts out in the hope of winning a life-changing record contract and being crowned the winner. As ever the judges will be rooting for the singers in their categories - Simon Cowell with the groups, Nicole Scherzinger with the overs, Sharon Osbourne with the girls and Louis Walsh with the boys - and there will be another live performance from a big celebrity name.