TV Sitcom Weddings

Meredith prepares for her long-awaited wedding day in a scene from the TV show "Grey's Anatomy." In honor of the wedding between Meredith (Ellen Pompeo) and Derek (Patrick Dempsey) on the show's 100th episode, fans are encouraged to donate to one of three charities close to the hearts of the show's characters on the fictional couple's wedding Web site called Knot. "What a Difference a Day Makes" airs Thursday, May 7 at 9 p.m. on ABC. (Craig Sjodin/AP Photo )