Sacha Baron Cohen turns 38 today. Ashanti is turning 29. Paul Simon is 68. Kelly Preston is turning 47. Kate Walsh of Grey's Anatomy and Private Practice is 42. Model Beverly Johnson is 57. Ivan Bart, the head of IMG Models, is turning 46. Billionaire Tom Tisch turns 55. Mega art dealer William Acquavella is 72. Sammy Hagar of Van Halen is 62. Access Hollywood's Billy Bush is turning 38. George Bush's former spokesman, Ari Fleischer, is 49. Marie Osmond is 50. Retired NFL star Jerry Rice is 47. Serena Altschul, the former MTV VJ and CBS News correspondent, is 39. Margaret Thatcher is 84. And Donald Trump's least famous child, Tiffany Trump, celebrates her 16th birthday today.