A recently single Usher, who is set to release a new album Monster in December, turns 31 today. Fellow singer Natalie Maines of the Dixie Chicks, who offstage is married to Heroes star Adrian Pasdar, is 35. Actress and one-time Dancing With The Stars contestant Stacy Keibler is 30. Roger Moore, an ex-James Bond, celebrates his 82nd birthday. And two fashion designers are celebrating today: Ralph Lauren is 70, and Isaac Mizrahi is 48.