Whether it's a metallic feathered headdress designed for Prince Charles' spouse, Camilla Parker-Bowles, or a crystal-encrusted lobster made for fashion editor Isabella Blow, Philip Treacy believes good hats stir emotions. "It's all about how it makes you feel," he said recently. "I like hats that make the heart beat faster." The Irish milliner has helped make mad hattery mainstream by designing eccentric, eye-catching headpieces for Givenchy, Chanel, Ralph Lauren and Donna Karen, among others. Thirty-six guests wore his creations to Prince William and Kate Middleton's blockbuster royal wedding, including Victoria Beckham (a military pillbox hat) and Princess Beatrice (a widely mocked flying spaghetti headpiece). Sometimes garish, frequently beautiful, Treacy's work rarely fails to turn heads.