What better way to get over a divorce then a night out on the tiles with party-girl Paris Hilton? Britney Spears and her new best friend have been seen on the party circuit most nights this week celebrating her newfound freedom. But it seems the pop singer, soon to be divorced from rap flop Kevin Federline, is having a little trouble keeping up with the millionaire heiress' drinking habits. Britney, 25, looking a bit worse for wear, flashed her white knickers as she struggled to get out of the car at Paris' Hollywood home. It comes just days after she...